Configuring ATM Routing and PNNI

To place calls between ATM end systems, signaling consults an IISP, a static routing protocol, or PNNI. PNNI is a dynamic routing protocol that provides quality of service (QoS) routes to signaling based on the QoS requirements specified in the call setup request.

This section provides an overview of PNNI with a comparison to IISP.

Dynamic Routing

PNNI is a dynamic routing protocol for ATM. PNNI is dynamic because it learns the network topology and reachability information with minimal configuration. It automatically adapts to network changes by advertising topology state information.

In contrast, IISP is a static routing protocol. You must manually configure each route through the network. Because IISP static routing requires significant manual configuration and does not offer the scalability of PNNI hierarchy, it is best suited for use in small networks.

Source Routing

In a PNNI routing domain, the source ATM switch (or DSLAM) computes hierarchically complete routes for connection setups. This route information is included in the call setup signaling message.

In contrast, IISP uses hop-by-hop routing, where each switch or DSLAM that receives the connection setup message selects the next outgoing interface to which to forward the setup message. This selection is based on the mapping of destination addresses (in a routing table) to outgoing interfaces.

QoS Support

PNNI provides routes that satisfy quality of service (QoS) connection requests. PNNI selects routes through the network based on the administrative weight (AW) and other QoS parameters, such as

Available cell rate (AvCR)
Maximum cell transfer delay (maxCTD)
Peak-to-peak cell delay variation (CDV)
Cell loss ratio (CLR)

The primary metric used by PNNI is AW. If a connection requests either maxCTD or CDV or both, PNNI may not be able to compute an optimum route through the network. However, PNNI guarantees a route that meets or exceeds the criteria of all specified QoS parameters.

In contrast, IISP does not provide QoS support.

PNNI Hierarchy

The primary goal of the PNNI hierarchy is scalability. However, you can also use the PNNI hierarchy for other needs, such as creating an administrative boundary. For example, you can use the PNNI hierarchy to hide the internal details of a peer group from switches outside of the peer group.

The key components of the PNNI hierarchy are:

Lowest-level nodes—A logical node in the lowest level of the PNNI hierarchy.
Peer group—A group of logical nodes. Each node exchanges information with other members of the group, and all members maintain an identical view of the group.
Peer group leader (PGL)—A logical node within a peer group that summarizes the peer group and represents it as a single logical node at the next level of the PNNI hierarchy.
Logical group node (LGN)—A logical node that represents its lower level peer group in the next higher level peer group. Upon becoming a PGL, the PGL creates a parent LGN to represent the peer group as a single logical node at the next level. The PGL is a logical node within the peer group, and the associated LGN is a logical node in the next higher level peer group.

The lowest level of the PNNI hierarchy contains lowest-level nodes only. No higher levels are possible if all nodes within a peer group are configured as lowest-level nodes. If your network is relatively small and scalability is not a problem, and the PNNI hierarchy is not required for other reasons, the benefits of a flat PNNI network may far outweigh the benefits of a hierarchical PNNI network. Refer to the "Configuring the Lowest Level of the PNNI Hierarchy" section for more information.

The peer group, PGL, and LGN define the hierarchy and are needed to create multiple levels of the PNNI hierarchy. Refer to the "Configuring Higher Levels of the PNNI Hierarchy" section for more information.

Figure 11-1 shows a flat network topology, where every node maintains information about every physical link in the network and reachability information for every other node in the network.

Figure 11-1: Flat Network Topology

Figure 11-2 shows a PNNI hierarchical network topology. In a PNNI hierarchical network, the number of nodes, links, and reachable address prefixes visible from any one switch in the network are reduced exponentially as the flat network is migrated to a hierarchical network.

Figure 11-2: PNNI Hierarchical Network Topology

PNNI hierarchy has certain advantages and disadvantages that you should consider before you decide to implement it in your network.

An advantage of PNNI hierarchy is its ability to scale to very large networks. This scalability is because of the exponential reduction in size of the visible topology and amount of received topology state information at each switch in the network. These reductions improve the effectiveness of your network by reducing the control traffic, memory, and processing required by each switch in the network.
A disadvantage of PNNI hierarchy is the loss of information caused by topology aggregation. PNNI performs route computations based on its view of the network topology. Because a hierarchical view of the network is restricted, compared to a nonhierarchical (flat topology) view, routing decisions are not as effective as in a flat topology. In both cases, a path to the destination is selected; however, in most cases the path selected in a flat topology is more efficient. This trade-off between routing efficiency and scalability is not specific to PNNI; it is a known limitation of any hierarchical routing protocol.
The decision to implement a PNNI hierarchy depends on several factors, including
- The size of the network
- Type of network traffic
- Call setup activity
- The amount of processing and memory required to handle the PNNI control traffic

: Because you must consider several factors, and their interdependency is not easily quantifiable, it is not possible to specify the exact number of nodes above which a flat network must be migrated to a hierarchical network. A high CPU load caused by PNNI control traffic is a strong indication that a hierarchical organization of the topology is required.

ATM Address Description

This section describes ATM addresses.

ATM Address Autoconfiguration

The DSLAM is equipped with a preconfigured 20-byte ATM address. This preconfigured address provides plug-and-play operation in isolated flat topology ATM networks. Although the preconfigured addresses are globally unique, they are not suitable for connection to service provider networks or within hierarchical PNNI networks. Furthermore, address summarization is not possible beyond the level of one switch.

The preconfigured ATM address format provided by Cisco Systems is shown in Figure 11-3.

Figure 11-3: Cisco Default ATM Address

All preconfigured addresses share the same 7-byte address prefix. This prefix allows all lowest-level PNNI nodes to generate the same default peer group identifier at level 56. When you interconnect multiple switches, one large autoconfigured peer group is created at level 56. The next six bytes comprise the MAC address of the switch. The 7-byte address prefix combined with the 6-byte MAC address provide a 13-byte prefix that uniquely identifies each switch. This 13-byte prefix is also the default ILMI address prefix and is used by ILMI for address registration and summarization.

ATM Address Formats

The address formats used in PNNI are:

The ATM End System Address (AESA). AESAs are 20 octets and are derived from the ISO definition of NSAPs. You can further classify AESAs based on the first octet, called the Authority and Format Identifier (AFI). The ATM Forum specifications through UNI Version 4.0 specify only three valid types of AFI: E.164, ICD, and DCC. However, future ATM Forum specifications will allow any AFI that has binary encoding of the Domain Specific Part (DSP) and a length of 20 octets. The DSLAM does not restrict the AFI values.
E.164 numbers (also known as native E.164 numbers) are supported on UNI and IISP interfaces, but are not directly supported by PNNI. Instead, these are supported indirectly through use of the E.164 AESA format.

Note See the ATM Forum UNI specifications for more information.

E.164 AESA Prefixes

PNNI address prefixes are usually created by taking the first p (0 to 152) bits of an address. Because of the encoding defined for E.164 AESAs, this creates difficulties when native E.164 numbers are used with E.164 AESAs.

The encoding defined for E.164 AESAs in the ATM Forum UNI specifications is shown in Figure 11-4.

Figure 11-4: Normal Encoding of E.164 AESAs (Right-Justified)

In normal encoding, the international E.164 number is right-justified in the IDI part, with leading semi-octet zeros (0) used to fill any unused spaces. Because the international E.164 number varies in length and is right justified you must configure several E.164 AESA prefixes to represent reachability information to the international E.164 number prefix. These E.164 AESA prefixes differ only in the number of leading zeros between the AFI and the international E.164 number.

For example, all international E.164 numbers that represent destinations in Germany begin with the country code 49. The length of international E.164 numbers in Germany varies between 9
and 12 digits. To configure static routes to all E.164 numbers in Germany, configure static routes to this set of E.164 AESA prefixes:

45.00049
45.000049
45.0000049
45.00000049

E.164 numbers that share a common prefix can be summarized by a single reachable address prefix, even when the corresponding set of full E.164 numbers varies in length. For this reason, in PNNI 2.0 the encoding of E.164 address prefixes is modified to a left-justified format, as shown in Figure 11-5.

Figure 11-5: PNNI 2.0 Encoding of E.164 AESAs (Left-Justified)

The left-justified encoding of the international E.164 number within the IDI allows for a single E.164 AESA prefix to represent reachability to all matching E.164 numbers, even when the matching E.164 numbers vary in length. Before PNNI routing looks up a destination address to find a route to that address, it converts the destination address from the call setup in the same way and then carries out the longest match lookup.

Note The converted encoding of the E.164 AESA is not used in PNNI signaling, even in PNNI 2.0. The conversion is only used for PNNI reachable address prefixes, and when determining the longest matching address prefix for a given AESA. Full 20-byte AESAs are always encoded as shown in Figure 11-4.

The DSLAM supports the PNNI 2.0 encoding of E.164 AESAs with the aesa embedded-number left-justified command. When you enter this command, all reachable address prefixes with the E.164 AFI are automatically converted into the left-justified encoding format. This includes reachable address prefixes advertised by remote PNNI nodes, ATM static routes, summary address prefixes, routes learned by ILMI, and reachable address prefixes installed by the switch automatically (that is, representing the switch address and the soft PVC addresses on this switch). This affects the atm route, auto-summary, summary-address, show atm route, and show atm pnni summary commands. The atm address, atm prefix, and show atm addresses commands are not affected because they do not use PNNI address prefixes.

Note All switches or ATM DSLAMs in the PNNI routing domain must have the same configuration by entering the aesa embedded-number left-justified command.

Obtaining ATM Addresses

You can categorize ATM addresses by ownership: customer-owned ATM addresses and service provider ATM addresses.

If you have a private network, you can obtain ATM addresses from these sources:

An ATM service provider—Any AESA format is acceptable.
The national registration authority— In the United States, the national registration authority is ANSI. In the United Kingdom, the national registration authority is FEI.

In customer-owned ATM addresses, the main part of the address is allocated directly to a private networking customer by a national or world registration authority. A customer owned ATM address (owned by Cisco) is preconfigured on each DSLAM. If you do not implement a hierarchy in your PNNI network, you can use the preconfigured ATM address.

In service provider ATM addresses, the main part of the address is allocated to the network operator by the appropriate national or world registration authority. The operator may then suballocate part of the address space to customers.

ATM service providers can obtain these types of ATM addresses:

E.164 numbers or E.164 AESAs from the ITU or the national numbering authority.
ICD AESAs from the British Standards Institute (BSI) by way of a national registration authority.
DCC AESAs from the national registration authority. In the U.S.A., the national registration authority is American National Standards Institute (ANSI). In the United Kingdom, the national registration authority is FEI.

Designing an ATM Address Plan

Your ATM address plan is key to efficient operation and management of PNNI networks. When you design an ATM address plan, the most important points to remember are:

Your ATM address prefixes must be globally unique.
The addresses must be hierarchical, corresponding to your network topology.
You must plan for future network expansion.

Globally Unique ATM Address Prefixes

You can obtain globally unique address prefixes from a national or world registration authority or they can be suballocated to you from a service provider's address space. Make sure that the addresses you assign in your network are derived from a globally unique address prefix, as shown in Figure 11-6.

Figure 11-6: Unique ATM Address Prefix Used to Assign ATM Addresses

For more information, refer to the "Obtaining ATM Addresses" section.

Hierarchical Addresses

The HO-DSP remainder, the part of the address between the assigned ATM address prefix and the ESI, should be assigned in a hierarchical manner. All systems in the network share the assigned ATM address prefix.

You can further subdivide the assigned address space by providing longer prefixes to different regions of the network. Within each peer group, be certain that the first level bits of each switch address matches the corresponding bits of the Peer Group Identifier (PGI) value. An example of a hierarchical address assignment is shown in Figure 11-7.

Figure 11-7: Sample Hierarchical Address Assignment

Note that the address prefix is longer at each lower level of the PNNI hierarchy shown in Figure 11-7.

The advantages of hierarchical address assignment include

Greatly increased scalability by minimizing the number of PNNI routes stored and processed by each node
Simplified configuration and management of the PNNI hierarchy

When the ATM network topology (which consists of switches, links, and virtual path [VP] tunnels) differs from the logical topology (which consists of VPNs and virtual LANs), it is important that the address hierarchy follow the network topology. You can construct the logical topology using other features, such as emulated LANs or Closed User Groups (CUGs).

Planning for Future Growth

When you are constructing the address hierarchy, it is important to plan ahead for the maximum number of levels that you might need for future growth. Not all levels in the addressing hierarchy need to be used by PNNI. It is possible to run with fewer PNNI levels in the beginning, and then migrate to more levels of hierarchy in the future. For example, you can configure the network as one large peer group where the PGI value is based on the assigned ATM address prefix. By planning ahead, you can easily migrate to more levels of hierarchy without manually renumbering all of the switches and end systems.

You can subdivide the HO-DSP remainder to allow for upward and downward future growth. For example, assume that you have 6 octets available for the HO-DSP remainder: 8 through 13 (as shown in Figure 11-8).

Figure 11-8: HO-DSP Remainder Subdivision Example

The HO-DSP remainder in this example spans levels 56 through 104. To allow for future expansion at the lowest level of the hierarchy, you must provide sufficient addressing space in the HO-DSP remainder to accommodate all future switches.

Assume that you start with the lowest level at 88. For administrative purposes, in the future you might want to group some of these switches into peer groups where additional switches will be added. For those switches that will be part of the new peer group you should assign addresses that can be easily clustered into a level 96 peer group. These addresses share a common 12th octet, leaving the 13th octet for downward future expansion.

The octet pairs (12 and 13) for these switches could be: (01, 00), (02, 00), (03, 00) and so on, while switches that will be added in the future could be: (02, 01), (02, 02), (02, 03) and so on.

This type of addressing scheme leaves room for expansion without requiring address modification. If you add a hierarchical level 96, the switches will form a new peer group at level 96.

Although you started with no more than 256 switches at the lowest level, by expanding this to two levels in the future, you are able to accommodate up to 65,536 switches in the same region.

Figure 11-9 shows an example of HO-DSP assignment.

Figure 11-9: Example of HO-DSP Assignment for Future Expansion

By following similar guidelines, you can plan for future expansion in the upward and downward direction. Specifically, you can expand upward by adding hierarchical levels as your network grows in size.

Configuring IISP

This section describes the procedures necessary for IISP configuration.

Configuring the Routing Mode

You can restrict the ATM routing software to operate in static mode. In this mode, call routing is restricted to only the static configuration of ATM routes, disabling operation of any dynamic ATM routing protocols, such as PNNI.

The atm routing-mode command is different from deleting all PNNI nodes using the node command and affects ILMI autoconfiguration. If the switch or DSLAM is configured using static routing mode on each interface, the switch ILMI variable atmfAtmLayerNniSigVersion is set to IISP. This causes either of these events to occur:

ILMI autoconfiguration on the interfaces between two switches determines the interface type as IISP.
The switch on the other side indicates that the Network-to-Network Interface (NNI) signaling protocol is not supported.

Note The atm routing-mode command is activated only after the next software reload. The switch continues to operate in the current mode until the software is reloaded.

To configure the routing mode, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm routing-mode static

Configure the ATM routing mode to static.

2
end

Exit configuration mode.

3
copy running-config startup-config

Write the running configuration to the startup configuration.

4
reload

Reload the switch software.

Step	Command	Task
1	atm routing-mode static	Configure the ATM routing mode to static.
2	end	Exit configuration mode.
3	copy running-config startup-config	Write the running configuration to the startup configuration.
4	reload	Reload the switch software.

Example

This example shows how to use the atm routing-mode static command to restrict the switch operation to static routing mode and displays the result:

DSLAM(config)# atm routing-mode static
This Configuration Will Not Take Effect Until Next Reload.
 
DSLAM(config)# end
 
DSLAM# copy running-config startup-config
Building configuration...
[OK]
 
DSLAM# reload
 
DSLAM# show running-config
Building configuration...
 
Current configuration:
!
version 11.2
no service pad
service udp-small-servers
service tcp-small-servers
!
hostname DSLAM
!
!
username dtate
ip rcmd remote-username dplatz
!
atm e164 translation-table
 e164 address 1111111 nsap-address 11.111111111111111111111111.112233445566.11
 e164 address 2222222 nsap-address 22.222222222222222222222222.112233445566.22
 e164 address 3333333 nsap-address 33.333333333333333333333333.112233445566.33
!
atm routing-mode static
atm address 47.0091.8100.0000.0040.0b0a.2b81.0040.0b0a.2b81.00
!
interface CBR0/0
 no ip address
 
<Information Deleted>

This example shows how to reset the switch operation back to PNNI if the DSLAM is operating in static mode:

DSLAM(config)# no atm routing-mode static
This Configuration Will Not Take Effect Until Next Reload.
 
DSLAM(config)# end
 
DSLAM# copy running-config startup-config
Building configuration...
[OK]
 
DSLAM# reload

Configuring the ATM Address

If you are planning to implement only a flat topology network (and have no future plans to migrate to PNNI hierarchy), you can skip this section and use the preconfigured ATM address assigned by Cisco Systems.

Note For information about ATM address considerations, refer to the "ATM Address Description" section.

To change the active ATM address follow these steps, beginning in global configuration mode:

Step
Command
Task

1
atm address atm-address

Configure the ATM address for the DSLAM.

2
end

Return to privileged EXEC mode.

3
show atm addresses

Verify the new address.

4
configure [terminal]

Enter configuration mode from the terminal.

5
no atm address atm_address

At the configuration mode prompt, remove the old ATM address from the DSLAM.

Step	Command	Task
1	atm address atm-address	Configure the ATM address for the DSLAM.
2	end	Return to privileged EXEC mode.
3	show atm addresses	Verify the new address.
4	configure [terminal]	Enter configuration mode from the terminal.
5	no atm address atm_address	At the configuration mode prompt, remove the old ATM address from the DSLAM.

Example

This example shows how to add the ATM address prefix 47.0091.8100.5670.000.0ca7.ce01 and remove the old address from the DSLAM and displays the result. Using the ellipses (...) adds the default Media Access Control (MAC) address as the last six bytes.

DSLAM(config)# atm address 47.0091.8100.5670.0000.0ca7.ce01...
 
DSLAM(config)# no atm address 47.0091.8100.0000.0041.0b0a.1081...
 
DSLAM# show atm addresses
 
Switch Address(es):
  47.00918100000000410B0A1081.00410B0A1081.00 active
  47.00918100567000000CA7CE01.00410B0A1081.00 
 
Soft VC Address(es):
Soft VC Address(es):
  47.0091.8100.0000.007b.f444.7801.4000.0c80.0010.00 ATM0/1
  47.0091.8100.0000.007b.f444.7801.4000.0c80.0020.00 ATM0/2
 
ILMI Switch Prefix(es):
  47.0091.8100.0000.007b.f444.7801
 
ILMI Configured Interface Prefix(es):
 
LECS Address(es):

Configuring Static Routes

Use the atm route command to configure a static route. A static route attached to an interface allows all ATM addresses matching the configured address prefix to be reached through that interface.

Note For private UNIs where ILMI address registration is not used, internal-type static routes should be configured to a 19-byte address prefix representing the attached end system.

To configure a static route, use this global configuration command:

Command
Task

atm route atm-address-prefix atm slot/port
[e164-address e164-address [number-type {international | local | national | subscriber}] [internal] [scope 1-15]

Specify a static route to a reachable address prefix.

Command	Task
atm route atm-address-prefix atm slot/port [e164-address e164-address [number-type {international \| local \| national \| subscriber}] [internal] [scope 1-15]	Specify a static route to a reachable address prefix.

Examples

This example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0:

DSLAM(config)# atm route 47.00918100000000410B0A1081 atm 0/0

This example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0 configured with a scope 1 associated:

DSLAM(config)# atm route 47.0091.8100.0000 atm 0/0 scope 1

This example shows the ATM static route configuration using the show atm route EXEC command:

DSLAM# show atm route
 
Codes: P - installing Protocol (S - Static, P - PNNI, R - Routing control),
       T - Type (I - Internal prefix, E - Exterior prefix, SE -
                 Summary Exterior prefix, SI - Summary Internal prefix,
                 ZE - Suppress Summary Exterior, ZI - Suppress Summary Internal)
 
P  T Node/Port        St Lev Prefix
~ ~~ ~~~~~~~~~~~~~~~~ ~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
S  E 1   ATM0/0     DN 56  47.0091.8100.0000/56
S  E 1   ATM0/0     DN 0   47.0091.8100.0000.00/64
                             (E164 Address 1234567)
R SI 1   0        UP 0   47.0091.8100.0000.0041.0b0a.1081/104
R  I 1   ATM0/0   UP 0   47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081/152
R  I 1   ATM0/0   UP 0   47.0091.8100.0000.0041.0b0a.1081.4000.0c/128
R SI 1   0            UP 0   47.0091.8100.5670.0000.0000.0000/104
R  I 1     ATM0/0     UP 0   47.0091.8100.5670.0000.0000.0000.0040.0b0a.1081/152
R  I 1   ATM0/0     UP 0   47.0091.8100.5670.0000.0000.0000.4000.0c/128

Configuring PNNI

This section describes all of the procedures necessary for you to create a basic PNNI configuration.

Configuring PNNI Without Hierarchy

The DSLAM defaults to a working PNNI configuration suitable for operation in isolated flat topology ATM networks. The DSLAM comes with a globally unique preconfigured ATM address. Manual configuration is not required if you

Have a flat network topology
Do not plan to connect the DSLAM to a service provider network
Do not plan to migrate to a PNNI hierarchy in the future

If you plan to migrate your flat network topology to a PNNI hierarchical topology, proceed to the next section.

Configuring the Lowest Level of the PNNI Hierarchy

This section describes how to configure the lowest level of the PNNI hierarchy. The lowest-level nodes comprise the lowest level of the PNNI hierarchy. When only the lowest-level nodes are configured, there is no hierarchical structure. If your network is relatively small and you want the benefits of PNNI, but do not need the benefits of a hierarchical structure, follow the procedures in this section to configure the lowest level of the PNNI hierarchy.

To implement multiple levels of PNNI hierarchy, first complete the procedures in this section and then proceed to the "Configuring Higher Levels of the PNNI Hierarchy" section.

The lowest level PNNI configuration includes these procedures:

Configuring an ATM Address and PNNI Node Level
Configuring Static Routes
Configuring a Summary Address
Configuring Scope Mapping

Configuring an ATM Address and PNNI Node Level

If you are planning to implement a:

Flat topology network (and have no future plans to migrate to PNNI hierarchy), you can skip this section and use the preconfigured ATM address assigned by Cisco Systems.
PNNI hierarchy, follow the procedure in this section to configure an ATM address and the PNNI node level.

The DSLAM is preconfigured as a single lowest-level PNNI node (locally identified as node 1) with a level of 56. The system calculates the node ID and peer group ID based on the current active ATM address.

To configure a node in a higher level of the PNNI hierarchy, the value of the node level must be a smaller number than the previous node. For example, a three-level hierarchical network could progress from level 72 to level 64 to level 56. Notice that the level numbers graduate from largest at the lowest level (72) to smallest at the highest level (56). (See Figure 11-7 earlier in this chapter.)

To change the active ATM address, create a new address, verify that it exists, and then delete the current active address. After you have entered the new ATM address, disable node 1 and then reenable it. At the same time, you can change the node level if required for your configuration. The identifiers for all higher level nodes are recalculated based on the new ATM address.

Caution The system does not recalculate node IDs and peer group IDs until the node is disabled and then re-enabled.

Note For information about ATM address considerations, refer to "ATM Address Description".

To change the active ATM address, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm address atm_address

At the configuration mode prompt, configure the new ATM address for the DSLAM.

2
end

Return to privileged EXEC mode.

3
show atm addresses

Verify the new address.

4
configure [terminal]

Enter configuration mode from the terminal.

5
no atm address atm_address

At the configuration mode prompt, remove the old ATM address from the DSLAM.

6
atm router pnni

At the configuration mode prompt, enter ATMrouter PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

7
node 1 disable

At the configure ATM router prompt, disable the PNNI node.

8
node 1 level level enable

Reenable the node. You can also change the node level if required for your configuration.

Step	Command	Task
1	atm address atm_address	At the configuration mode prompt, configure the new ATM address for the DSLAM.
2	end	Return to privileged EXEC mode.
3	show atm addresses	Verify the new address.
4	configure [terminal]	Enter configuration mode from the terminal.
5	no atm address atm_address	At the configuration mode prompt, remove the old ATM address from the DSLAM.
6	atm router pnni	At the configuration mode prompt, enter ATMrouter PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.
7	node 1 disable	At the configure ATM router prompt, disable the PNNI node.
8	node 1 level level enable	Reenable the node. You can also change the node level if required for your configuration.

Example

This example changes the ATM address of the DSLAM from the autoconfigured address 47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081.00 to the new address prefix 47.0091.8100.5670.0000.0000.1122.0041.0b0a.1081.00, and causes the node identifier and peer group identifier to be recalculated:

DSLAM(config)# atm address 47.0091.8100.5670.0000.0000.1122...
 
DSLAM(config)# no atm address 47.0091.8100.0000.0041.0b0a.1081...
 
DSLAM(config)# atm router pnni
 
DSLAM(config-atm-router)# node 1 disable
 
DSLAM(config-pnni-node)# node 1 enable

This example shows the PNNI node configuration using the show atm pnni local-node privileged EXEC command:

DSLAM# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: eng_1
  System address          47.0091810000000002EB1FFE00.0002EB1FFE00.01
  Node ID          56:160:47.0091810000000002EB1FFE00.0002EB1FFE00.00
  Peer group ID        56:160:47.0000.0000.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 1, No. of neighbors 0
  Parent Node Index: 2
  Node Allows Transit Calls
  Node Representation: simple
 
  Hello interval 15 sec, inactivity factor 5,
  Hello hold-down 10 tenths of sec
  Ack-delay 10 tenths of sec, retransmit interval 5 sec,
  Resource poll interval 5 sec
  SVCC integrity times: calling 35 sec, called 50 sec,
  Horizontal Link inactivity time 120 sec,
  PTSE refresh interval 1800 sec, lifetime factor 200 percent,
  Min PTSE interval 10 tenths of sec
  Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
  Default administrative weight mode: uniform
  Max admin weight percentage: -1
  Next resource poll in 3 seconds
  Max PTSEs requested per PTSE request packet: 32
  Redistributing static routes: Yes

Configuring Static Routes

Because PNNI is a dynamic routing protocol, static routes are not required between nodes that support PNNI. However, you can extend the routing capability of PNNI beyond nodes that support PNNI to

Connect to nodes outside of a peer group that do not support PNNI
Define routes to end systems that do not support ILMI

Use the atm route command to configure a static route. A static route attached to an interface allows all ATM addresses matching the configured address prefix to be reached through that interface.

Note You can connect two PNNI peer groups using the IISP protocol. Connecting PNNI peer groups requires that you configure a static route on the IISP interfaces, allowing connections to be set up across the IISP links.

To configure a static route connection, use this global configuration command:

Command
Task

atm route atm-address-prefix atm slot/port
[e164-address e164-address [number-type {international | local | national | subscriber}]] [internal] [scope 1-15]

Specify a static route to a reachable address prefix.

Command	Task
atm route atm-address-prefix atm slot/port [e164-address e164-address [number-type {international \| local \| national \| subscriber}]] [internal] [scope 1-15]	Specify a static route to a reachable address prefix.

Examples

This example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0:

DSLAM(config)# atm route 47.00918100000000410B0A1081 atm 0/0

This example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0 configured with a scope 1 associated:

DSLAM(config)# atm route 47.0091.8100.0000 atm 0/0 scope 1

This example shows the ATM static route configuration using the show atm route EXEC command:

DSLAM# show atm route
 
Codes: P - installing Protocol (S - Static, P - PNNI, R - Routing control),
       T - Type (I - Internal prefix, E - Exterior prefix, SE -
                 Summary Exterior prefix, SI - Summary Internal prefix,
                 ZE - Suppress Summary Exterior, ZI - Suppress Summary Internal)
 
P  T Node/Port        St Lev Prefix
~ ~~ ~~~~~~~~~~~~~~~~ ~~ ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
S  E 1   ATM0/0     DN 56  47.0091.8100.0000/56
S  E 1   ATM0/0     DN 0   47.0091.8100.0000.00/64
                             (E164 Address 1234567)
R SI 1   0            UP 0   47.0091.8100.0000.0041.0b0a.1081/104
R  I 1     ATM0/0     UP 0   47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081/152
R  I 1   ATM0/0     UP 0   47.0091.8100.0000.0041.0b0a.1081.4000.0c/128
R SI 1   0            UP 0   47.0091.8100.5670.0000.0000.0000/104
R  I 1     ATM0/0     UP 0   47.0091.8100.5670.0000.0000.0000.0040.0b0a.1081/152
R  I 1   ATM0/0     UP 0   47.0091.8100.5670.0000.0000.0000.4000.0c/128

Configuring a Summary Address

You can configure summary addresses to reduce the amount of information advertised by a PNNI node and contribute to scalability in large networks. Each summary address consists of a single reachable address prefix that represents a collection of end system or node addresses.

We recommend that you use summary addresses when all end system addresses that match the summary address are directly reachable from the node. However, this is not always required because routes are always selected by nodes advertising the longest matching prefix to a destination address.

By default, each lowest-level node has a summary address equal to the 13-byte address prefix of the ATM address of the DSLAM. This address prefix is advertised into its peer group.

You can configure multiple addresses for a single DSLAM which are used during ATM address migration. ILMI registers end systems with multiple prefixes during this period until an old address is removed. PNNI automatically creates 13-byte summary address prefixes from all of its ATM addresses.

You must configure summary addresses (other than the defaults) on each node. Each node can have multiple summary address prefixes. Use the summary-address command to manually configure summary address prefixes.

Note The no auto-summary command removes the default summary addresses. Use the no auto-summary command when systems that match the first 13 bytes of the ATM addresses of your DSLAM are attached to different devices. You can also use this command for security purposes.

To configure a summary address, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
node node_index

At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.

3
no auto-summary

Remove the default summary addresses.

4
summary-address address_prefix

Configure the ATM PNNI summary address prefix.

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.
2	node node_index	At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.
3	no auto-summary	Remove the default summary addresses.
4	summary-address address_prefix	Configure the ATM PNNI summary address prefix.

Examples

This example removes the default summary addresses and adds summary address 47.009181005670:

DSLAM(config)# atm router pnni
 
DSLAM(config-atm-router)# node 1
 
DSLAM(config-pnni-node)# no auto-summary
 
DSLAM(config-pnni-node)# summary-address 47.009181005670

This example shows the ATM PNNI summary address configuration using the show atm pnni summary privileged EXEC command:

DSLAM# show atm pnni summary
 
Codes: Node - Node index advertising this summary
       Type - Summary type (INT - internal, EXT - exterior)
       Sup  - Suppressed flag (Y - Yes, N - No)
       Auto - Auto Summary flag (Y - Yes, N - No)
       Adv  - Advertised flag (Y - Yes, N - No)
 
 Node Type Sup Auto Adv  Summary Prefix
 ~~~~ ~~~~ ~~~ ~~~~ ~~~  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  1   Int   N   Y    Y   47.0091.8100.0000.0040.0b0a.2a81/104
  2   Int   N   Y    N   47.01b1.0000.0000.0000.00/80

Configuring Scope Mapping

The PNNI address scope allows you to restrict advertised reachability information within configurable boundaries.

Note On UNI and IISP interfaces, the scope is specified in terms of organizational scope values ranging from 1 (local) to 15 (global). (Refer to the ATM Forum UNI Signaling Version 4.0 specification for more information.)

In PNNI networks, the scope is specified in terms of PNNI levels. The mapping from organizational scope values used at UNI and IISP interfaces to PNNI levels is configured on the lowest-level node. The mapping can be determined automatically (which is the default setting) or manually, depending on the configuration of the scope mode command.

In manual mode, if you modify the level of node 1, make sure you also reconfigure the scope map to avoid unintended suppression of reachability advertisements. Misconfiguring the scope map could cause addresses to remain unadvertised.

In automatic mode, the UNI to PNNI level mapping is automatically reconfigured each time the level of the node 1 is modified. The automatic reconfiguration prevents misconfigurations caused by node level modifications. Automatic adjustment of scope mapping uses the values shown in Table 11-1.

Table 11-1: Scope Mapping Table

Organizational
Scope ATM Forum PNNI 1.0
Default Level Automatic Mode PNNI
Level

1 to 3

96

Minimum (l,96)

4 to 5

80

Minimum (l,80)

6 to 7

72

Minimum (l,72)

8 to 10

64

Minimum (l,64)

11 to 12

48

Minimum (l,48)

13 to 14

32

Minimum (l,32)

15 (global)

0

0

Organizational Scope	ATM Forum PNNI 1.0 Default Level	Automatic Mode PNNI Level
1 to 3	96	Minimum (l,96)
4 to 5	80	Minimum (l,80)
6 to 7	72	Minimum (l,72)
8 to 10	64	Minimum (l,64)
11 to 12	48	Minimum (l,48)
13 to 14	32	Minimum (l,32)
15 (global)	0	0

If you enter the scope mode automatic command, this ensures that all organizational scope values cover an area at least as wide as the current node's peer group. Configuring the scope mode to manual disables this feature and no changes can be made without explicit configuration.

To configure the PNNI scope mapping, perform these steps, beginning in global configuration mode:

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#`.`
2	node node_index	At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#`.`
3	scope mode {automatic \| manual}	Configure scope mode as manual.¹
4	scope map low-org-scope [high-org-scope] level level-number	Configure node scope mapping.

Example

This example shows how to configure PNNI scope mapping manually so that organizational scope values 1 through 8 map to PNNI level 72 and displays the result:

DSLAM(config)# atm router pnni
 
DSLAM(config-atm-router)# node 1
 
DSLAM(config-pnni-node)# scope mode manual
 
DSLAM(config-pnni-node)# scope map 1 8 level 72
 
DSLAM# show atm pnni scope
UNI scope   PNNI Level
~~~~~~~~~   ~~~~~~~~~~
(1  - 10)      56
(11 - 12)      48
(13 - 14)      32
(15 - 15)      0
 
Scope mode: manual

Configuring Higher Levels of the PNNI Hierarchy

This section describes the procedures to configure higher levels of PNNI hierarchy.

After you have configured the lowest level of the PNNI hierarchy (see the section, "Configuring the Lowest Level of the PNNI Hierarchy" section), you can complete the PNNI hierarchical structure by configuring peer group leaders (PGLs) and logical group nodes (LGNs).

Each peer group can contain one active PGL. The PGL is a logical node within the peer group that collects data about the peer group to represent it as a single node to the next PNNI hierarchical level.

Upon becoming a PGL, the PGL creates a parent LGN. The LGN represents the PGL's peer group within the next higher level peer group. The LGN aggregates and summarizes information about its child peer group and floods that information into its own peer group.

The LGN also distributes information received from its peer group to the PGL of its child peer group for flooding. Figure 11-10 shows an example of PGLs and LGNs.

Figure 11-10: PGLs and LGNs

To create the PNNI hierarchy, select DSLAMs that are eligible to become PGLs at each level of the hierarchy. Nodes can become PGLs through the peer group leader election process. Each node has a configured election priority.

To be eligible for election, the configured priority must be greater than zero and a parent node must be configured. Normally the node with the highest configured leadership priority in a peer group is elected PGL. You can configure multiple nodes in a peer group with a non-zero leadership priority so that if one PGL becomes unreachable, the node configured with the next highest election leadership priority becomes the new PGL.

Note The choice of PGL does not directly affect the selection of routes across a peer group.

Because any one peer group can consist of both lowest level nodes and LGNs, lowest level nodes should be preferred as PGLs. Configuring the network hierarchy with multiple LGNs at the same DSLAM creates additional PNNI processing and results in slower recovery from failures. Selecting DSLAMs for election with more processing capability (for example, because a smaller volume of call processing compared to others) may be better.

We recommend that each node in a peer group that can become a PGL be assigned the same parent node configuration.

Configuring a Logical Group Node and Peer Group Identifier

You can configure a new LGN by entering the node command with an unused node index value between 2 and 8.

The LGN is created only when the child node in the same DSLAM (that is, the node whose parent configuration points to this node) is elected PGL of the child peer group.

The peer group identifier defaults to a value created from the first part of the child peer group identifier, and does not need to be specified. If you want a non-default peer group identifier, you must configure all logical nodes within a peer group with the same peer group identifier.

Higher level nodes only become active if

A lower-level node specifies the higher-level node as a parent.
The election leadership priority of the child node is configured with a non-zero value and is elected as the PGL.

To configure a LGN and peer group identifier, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

Enter ATM router PNNI mode. The prompt changes to DSLAM(config-atm-router)#.

2
node node_index level level [lowest] [peer-group-identifier dd:xxx] [enable | disable]

Configure the logical node and optionally its peer group identifier. Configure each logical node in the peer group with the same peer group identifier. When you have more than one logical node on the same DSLAM, you must specify a different index number to distinguish it from node 1.

Step	Command	Task
1	atm router pnni	Enter ATM router PNNI mode. The prompt changes to DSLAM(config-atm-router)#.
2	node node_index level level [lowest] [peer-group-identifier dd:xxx] [enable \| disable]	Configure the logical node and optionally its peer group identifier. Configure each logical node in the peer group with the same peer group identifier. When you have more than one logical node on the same DSLAM, you must specify a different index number to distinguish it from node 1.

Example

This example shows how to create a new node 2 with a level of 56 and a peer group identifier of 56:47009111223344 and displays the result. Notice that the PNNI level and the first two digits of the peer group identifier are the same:

DSLAM(config)# atm router pnni
 
DSLAM(config-atm-router)# node 2 level 56 peer-group-identifier 56:47009111223344 enable
 
DSLAM(config-pnni-node)# end
 
DSLAM# show atm pnni local-node 2
 
PNNI node 2 is enabled and not running
  Node name: Switch.2.56
  System address          47.009181000000000000000001.000000000001.02
  Node ID            56:0:00.000000000000000000000000.000000000001.00
  Peer group ID        56:47.0091.1122.3344.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: NONE
  Node Allows Transit Calls
  Node Representation: simple
 
  Hello interval 15 sec, inactivity factor 5,
  Hello hold-down 10 tenths of sec
  Ack-delay 10 tenths of sec, retransmit interval 5 sec,
  Resource poll interval 5 sec
  SVCC integrity times: calling 35 sec, called 50 sec,
  Horizontal Link inactivity time 120 sec,
  PTSE refresh interval 1800 sec, lifetime factor 200 percent,
  Min PTSE interval 10 tenths of sec
  Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
  Default administrative weight mode: uniform
  Max admin weight percentage: -1
  Max PTSEs requested per PTSE request packet: 32
  Redistributing static routes: No

Configuring the Node Name

PNNI node names default to names based on the host name. For example, if the host name is SanFran1, the default node name is also SanFran1. If you prefer node names that more accurately reflect the peer group, you can use the name command to change the default node name. For example, you could change the node name to Cal1 to represent the entire location of the peer group to which it belongs. Cisco recommends you choose a node name of 12 characters or less so that your screen displays remain well formatted and easy to read.

After you configure a node name, the system distributes it to all other nodes by PNNI flooding. This allows the node to be identified by its node name in PNNI show commands.

To configure the PNNI node name, perform these steps, beginning in global configuration mode:

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#`.`
2	node node_index	At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.
3	name name_string	Configure the node name.

Example

This example configures the name of the node as eng_1 using the name command, and displays the result:

DSLAM(config)# atm router pnni
 
DSLAM(config-atm-router)# node 1
 
DSLAM(config-pnni-node)# name eng_1
 
DSLAM# show atm pnni local-node
PNNI node 1 is enabled and running
  Node name: eng_1
  System address          47.0091810000000002EB1FFE00.0002EB1FFE00.01
  Node ID          56:160:47.0091810000000002EB1FFE00.0002EB1FFE00.00
  Peer group ID        56:16.0347.0000.0000.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 1, No. of neighbors 0
  Parent Node Index: 2
  Node Allows Transit Calls
  Node Representation: simple
 
  Hello interval 15 sec, inactivity factor 5,
  Hello hold-down 10 tenths of sec
  Ack-delay 10 tenths of sec, retransmit interval 5 sec,
  Resource poll interval 5 sec
  SVCC integrity times: calling 35 sec, called 50 sec,
  Horizontal Link inactivity time 120 sec,
  PTSE refresh interval 1800 sec, lifetime factor 200 percent,
  Min PTSE interval 10 tenths of sec
  Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
  Default administrative weight mode: uniform
  Max admin weight percentage: -1
  Next resource poll in 3 seconds
  Max PTSEs requested per PTSE request packet: 32
  Redistributing static routes: Yes

Configuring a Parent Node

For a node to be eligible to become a PGL within its own peer group, you must configure a parent node and an election leadership level (described in the section "Configuring the Node Election Leadership Priority" section). If the node is elected a PGL, the node specified by the parent command becomes the parent node and represents the peer group at the next hierarchical level.

To configure a parent node, perform these steps, beginning in global configuration mode:

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#`.`
2	node node_index	At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#`.`
3	parent node_index	Configure the parent node index.

Example

This example creates a parent node for node 1 and displays the result:

DSLAM(config)# atm router pnni
 
DSLAM(config-pnni-node)# node 1 
 
DSLAM(config-pnni-node)# parent 2
 
DSLAM# show atm pnni hierarchy
Locally configured parent nodes:
  Node          Parent
  Index  Level  Index   Local-node Status     Node Name
  ~~~~~  ~~~~~  ~~~~~~  ~~~~~~~~~~~~~~~~~~~~  ~~~~~~~~~~~~~~~~~~~~~~
  1      80     2       Enabled/ Running      DSLAM
  2      72     N/A     Enabled/ Running      DSLAM.2.72

Configuring the Node Election Leadership Priority

Normally the node with the highest election leadership priority is elected PGL. If two nodes share the same election priority, the node with the highest node identifier becomes the PGL. To be eligible for election, ensure that the configured priority is greater than zero. You can configure multiple nodes in a peer group with non-zero leadership priority so that if one PGL becomes unreachable, the node configured with the next highest election leadership priority becomes the new PGL.

Note The choice of PGL does not directly affect the selection of routes across the peer group.

The control for election is done through the assignment of leadership priorities. We recommend that the leadership priority space be divided into three tiers:

First tier—1 to 49
Second tier—100 to 149
Third tier—200 to 205

This subdivision exists because of the GroupLeaderIncrement variable. When a node becomes PGL, it increases the advertised leadership priority by a value of 50 to avoid instabilities after election.

Keep nodes that you do not want to become PGLs assigned to a default leadership priority value of 0.

If among the PGL candidates no node must be forced to be PGL, then assign all leadership priority values within the first tier. After a node is elected PGL, it remains PGL until it steps down a tier or is configured to step down.

If certain nodes must take precedence over nodes in the first tier, even if one is already PGL, leadership priority values can be assigned from the second tier. We recommend that you configure more than one node with a leadership priority value from the second tier. This prevents one unstable node with a larger leadership priority value from destabilizing the peer group repeatedly.

If you need a strict master leader, use the third tier.

Note The election leadership-priority command does not take effect unless you configured a parent node using the node and parent commands.

To configure the election leadership priority, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

Enter ATM router PNNI mode from the terminal.

2
node node_index

Enter node configuration mode.

3
election leadership-priority number

Configure the election leadership priority. The configurable range is from 0 to 205.

Step	Command	Task
1	atm router pnni	Enter ATM router PNNI mode from the terminal.
2	node node_index	Enter node configuration mode.
3	election leadership-priority number	Configure the election leadership priority. The configurable range is from 0 to 205.

Example

This example changes the election leadership priority for node 1 to 100 and displays the result:

DSLAM(config)# atm router pnni
 
DSLAM(config-pnni-node)# node 1
 
DSLAM(config-pnni-node)# election leadership-priority 100
 
DSLAM# show atm pnni election
 
PGL Status.............: PGL
Preferred PGL..........: (1) Switch
Preferred PGL Priority.: 255
Active PGL.............: (1) Switch
Active PGL Priority....: 255
Active PGL For.........: 00:01:07
Current FSM State......: PGLE Operating: PGL
Last FSM State.........: PGLE Awaiting Unanimity
Last FSM Event.........: Unanimous Vote
 
Configured Priority....: 205
Advertised Priority....: 255
Conf. Parent Node Index: 2
PGL Init Interval......: 15 secs
Search Peer Interval...: 75 secs
Re-election Interval...: 15 secs
Override Delay.........: 30 secs

This example shows all nodes in the peer group using the show atm pnni election peers command:

DSLAM# show atm pnni election peers
 
  Node No.   Priority   Connected   Preferred PGL
  ~~~~~~~~   ~~~~~~~~   ~~~~~~~~~   ~~~~~~~~~~~~~
  1          255        Yes         Switch
  9          0          Yes         Switch
  10         0          Yes         Switch
  11         0          Yes         Switch
  12         0          Yes         Switch

Configuring a Summary Address

You can use summary addresses to decrease the amount of information advertised by a PNNI node, and thereby contribute to scaling in large networks. Each summary address consists of a single reachable address prefix that represents a collection of end system or node addresses that begin with the given prefix. Only use summary addresses when all end system addresses that match the summary address are directly reachable from this node. However, this is not always required because routes are always selected to nodes advertising the longest matching prefix to a destination address.

Configure a single default summary address for each logical group node (LGN) in the PNNI hierarchy. The length of that summary for any LGN equals the level of the child peer group, and its value is equal to the first level bits of the child peer group identifier. This address prefix is advertised into the LGN's peer group.

Explicitly configure summary addresses other than defaults on each node. Use the summary-address command to manually configure summary address prefixes. A node can have multiple summary address prefixes.

Assign the same summary adddress lists to each node in a peer group that has a potential to become a PGL for its parent node configuration.

Note The no auto-summary command removes the default summary addresses. Use the no auto-summary command when systems that match the first 13 bytes of the ATM addresses of your DSLAM are attached to different DSLAMs.

To configure the ATM PNNI summary address prefix, perform these steps, beginning in global configuration mode:

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.
2	node node_index	At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.
3	no auto-summary	Remove the default summary addresses.
4	summary-address address_prefix	Configure the ATM PNNI summary address prefix.

Example

This example shows how to remove the default summary addresses and add summary address 47.009181005670 and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# node 1
DSLAM(config-pnni-node)# no auto-summary
DSLAM(config-pnni-node)# summary-address 47.009181005670
DSLAM# show atm pnni summary
 
Codes: Node - Node index advertising this summary
       Type - Summary type (INT - internal, EXT - exterior)
       Sup  - Suppressed flag (Y - Yes, N - No)
       Auto - Auto Summary flag (Y - Yes, N - No)
       Adv  - Advertised flag (Y - Yes, N - No)
 
 Node Type Sup Auto Adv  Summary Prefix
 ~~~~ ~~~~ ~~~ ~~~~ ~~~  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  1   Int   N   Y    Y   47.0091.8100.0000.0040.0b0a.2a81/104
  2   Int   N   Y    N   47.01b1.0000.0000.0000.00/80

PNNI Hierarchy Configuration Example

An example configuration for a three-level hierarchical topology is shown in Figure 11-11. The example shows the configuration of only 5 switches, although you can configure several other switches in each peer group.

Figure 11-11: Example Three-Level Hierarchical Topology

At the lowest level (level 72), the hierarchy represents two separate peer groups. Each of the four switches named T2 to T5 are eligible to become a PGL at two levels, and each has two configured ancestor nodes (a parent node or a parent node's parent).

Switch T1 has no configured ancestor nodes and is not eligible to become a PGL. As a result of the peer group leader election at the lowest level, switches T4 and T3 become leaders of their peer groups. Therefore, each switch creates an LGN at the second level (level 64) of the hierarchy.

As a result of the election at the second level of the hierarchy, logical group nodes SanFran.BldA and NewYork.BldB are elected as PGLs, creating logical group nodes at the highest level of the hierarchy (Level 56). At that level, the uplinks induced through level 64 form an aggregated horizontal link within the common peer group at level 56.

Examples

The examples that follow show the configurations for each switch and the outputs of the show atm pnni local-node command.

Switch NewYork.BldB.T1 Configuration

hostname NewYork.BldB.T1
atm address 47.0091.4455.6677.1144.1011.1233.0060.3e7b.3a01.00
atm router pnni
  node 1 level 72 lowest
  redistribute atm-static
 
NewYork.BldB.T1# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: NewYork.BldB.T1
  System address          47.009144556677114410111233.00603E7B3A01.01
  Node ID          72:160:47.009144556677114410111233.00603E7B3A01.00
  Peer group ID        72:47.0091.4455.6677.1144.0000.0000
  Level 72, Priority 0 0, No. of interfaces 3, No. of neighbors 2
  Parent Node Index: NONE
 
<information deleted>

Switch NewYork.BldB.T2 Configuration

hostname NewYork.BldB.T2
atm address 47.0091.4455.6677.1144.1011.1244.0060.3e5b.bc01.00
atm router pnni
node 1 level 72 lowest
  parent 2
  redistribute atm-static
  election leadership-priority 40
 node 2 level 64
  parent 3
  election leadership-priority 40
  name NewYork.BldB
 node 3 level 56
  name NewYork
 
NewYork.BldB.T2# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: NewYork.BldB.T2
  System address          47.009144556677114410111244.00603E5BBC01.01
  Node ID          72:160:47.009144556677114410111244.00603E5BBC01.00
  Peer group ID        72:47.0091.4455.6677.1144.0000.0000
  Level 72, Priority 40 40, No. of interfaces 3, No. of neighbors 1
  Parent Node Index: 2
 
<information deleted>
 
PNNI node 2 is enabled and not running
  Node name: NewYork.BldB
  System address          47.009144556677114410111244.00603E5BBC01.02
  Node ID           64:72:47.009144556677114400000000.00603E5BBC01.00
  Peer group ID        64:47.0091.4455.6677.1100.0000.0000
  Level 64, Priority 40 40, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: 3
 
<information deleted>
 
PNNI node 3 is enabled and not running
  Node name: NewYork
  System address          47.009144556677114410111244.00603E5BBC01.03
  Node ID           56:64:47.009144556677110000000000.00603E5BBC01.00
  Peer group ID        56:47.0091.4455.6677.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: NONE
 
<information deleted>

Switch NewYork.BldB.T3 Configuration

hostname NewYork.BldB.T3
atm address 47.0091.4455.6677.1144.1011.1255.0060.3e5b.c401.00
atm router pnni
 node 1 level 72 lowest
  parent 2
  redistribute atm-static
  election leadership-priority 45
 node 2 level 64
  parent 3
  election leadership-priority 45
  name NewYork.BldB
 node 3 level 56
  name NewYork
 
NewYork.BldB.T3# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: NewYork.BldB.T3
  System address          47.009144556677114410111255.00603E5BC401.01
  Node ID          72:160:47.009144556677114410111255.00603E5BC401.00
  Peer group ID        72:47.0091.4455.6677.1144.0000.0000
  Level 72, Priority 45 95, No. of interfaces 4, No. of neighbors 1
  Parent Node Index: 2
 
<information deleted>
 
PNNI node 2 is enabled and running
  Node name: NewYork.BldB
  System address          47.009144556677114410111255.00603E5BC401.02
  Node ID           64:72:47.009144556677114400000000.00603E5BC401.00
  Peer group ID        64:47.0091.4455.6677.1100.0000.0000
  Level 64, Priority 45 95, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: 3
 
<information deleted>
 
PNNI node 3 is enabled and running
  Node name: NewYork
  System address          47.009144556677114410111255.00603E5BC401.03
  Node ID           56:64:47.009144556677110000000000.00603E5BC401.00
  Peer group ID        56:47.0091.4455.6677.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 0, No. of neighbors 1
  Parent Node Index: NONE
 
<information deleted>

Switch SanFran.BldA.T4 Configuration

hostname SanFran.BldA.T4
atm address 47.0091.4455.6677.2233.1011.1266.0060.3e7b.2001.00
atm router pnni
 node 1 level 72 lowest
  parent 2
  redistribute atm-static
  election leadership-priority 45
 node 2 level 64
  parent 3
  election leadership-priority 45
  name SanFran.BldA
 node 3 level 56
  name SanFran
 
SanFran.BldA.T4# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: SanFran.BldA.T4
  System address          47.009144556677223310111266.00603E7B2001.01
  Node ID          72:160:47.009144556677223310111266.00603E7B2001.00
  Peer group ID        72:47.0091.4455.6677.2233.0000.0000
  Level 72, Priority 45 95, No. of interfaces 4, No. of neighbors 1
  Parent Node Index: 2
 
<information deleted>
 
PNNI node 2 is enabled and running
  Node name: SanFran.BldA
  System address          47.009144556677223310111266.00603E7B2001.02
  Node ID           64:72:47.009144556677223300000000.00603E7B2001.00
  Peer group ID        64:47.0091.4455.6677.2200.0000.0000
  Level 64, Priority 45 95, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: 3
<information deleted>
 
PNNI node 3 is enabled and running
  Node name: SanFran
  System address          47.009144556677223310111266.00603E7B2001.03
  Node ID           56:64:47.009144556677220000000000.00603E7B2001.00
  Peer group ID        56:47.0091.4455.6677.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 0, No. of neighbors 1
  Parent Node Index: NONE
 
<information deleted>

Switch SanFran.BldA.T5 Configuration

hostname SanFran.BldA.T5
atm address 47.0091.4455.6677.2233.1011.1244.0060.3e7b.2401.00
atm router pnni
 node 1 level 72 lowest
  parent 2
  redistribute atm-static
  election leadership-priority 10
 node 2 level 64
  parent 3
  election leadership-priority 40
  name SanFran.BldA
 node 3 level 56
  name SanFran
 
SanFran.BldA.T5# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: SanFran.BldA.T5
  System address          47.009144556677223310111244.00603E7B2401.01
  Node ID          72:160:47.009144556677223310111244.00603E7B2401.00
  Peer group ID        72:47.0091.4455.6677.2233.0000.0000
  Level 72, Priority 10 10, No. of interfaces 2, No. of neighbors 1
  Parent Node Index: 2
 
<information deleted>
 
PNNI node 2 is enabled and not running
  Node name: SanFran.BldA
  System address          47.009144556677223310111244.00603E7B2401.02
  Node ID           64:72:47.009144556677223300000000.00603E7B2401.00
  Peer group ID        64:47.0091.4455.6677.2200.0000.0000
  Level 64, Priority 40 40, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: 3
 
<information deleted>
 
PNNI node 3 is enabled and not running
  Node name: SanFran
  System address          47.009144556677223310111244.00603E7B2401.03
  Node ID           56:64:47.009144556677220000000000.00603E7B2401.00
  Peer group ID        56:47.0091.4455.6677.0000.0000.0000
  Level 56, Priority 0 0, No. of interfaces 0, No. of neighbors 0
  Parent Node Index: NONE
 
<information deleted>

Advanced PNNI Configuration

This section describes how to configure advanced PNNI features. The advanced features described in this section are not required to enable PNNI, but are provided to assist you in tuning your network performance.

Tuning Route Selection

This section describes how to tune the route selection in your PNNI network:

Configuring Background Route Computation
Configuring Link Selection
Configuring the Maximum Administrative Weight Percentage
Configuring the Precedence

Configuring Background Route Computation

The DSLAM supports these route selection modes:

On-demand—A separate route computation is performed each time a SETUP or ADD PARTY message is received over a UNI or IISP interface. In this mode, the most recent topology information received by this node is always used for each setup request.
Background routes—You can route calls using precomputed routing trees. In this mode, multiple background trees are precomputed for several service categories and QoS metrics. If no route can be found in the multiple background trees that satisfies the QoS requirements of a particular call, route selection reverts to on-demand route computation.

The background routes mode should be enabled in large networks where it will usually exhibit less-stringent processing requirements and better scalability. Route computation is performed at almost every poll interval when a significant change in the topology of the network is reported or when significant threshold changes have occurred since the last route computation.

To configure the background route computation, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
background-routes-enable {insignificant-threshold value |
poll-interval seconds}

Enable background routes and configure background route parameters.

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#`.`
2	background-routes-enable {insignificant-threshold value \| poll-interval seconds}	Enable background routes and configure background route parameters.

Examples

This example shows how to enable background routes and configures the background routes poll interval to 30 seconds:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# background-routes-enable poll-interval 30

This example shows the ATM PNNI background route configuration using the show atm pnni background status privileged EXEC command:

DSLAM# show atm pnni background status
 
Background Route Computation is Enabled
Background Interval is set at 10 seconds
Background Insignificant Threshold is set at 32

This example shows the ATM PNNI background route tables for CBR using the show atm pnni background routes privileged EXEC command:

DSLAM# show atm pnni background routes cbr
   
  Background Routes From CBR/AW Table
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  2 Routes To Node 2
      1. Hops 1. 1:ATM0/2 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
      2. Hops 1. 1:ATM0/1 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
   
  1 Routes To Node 5
      1. Hops 1. 1:ATM1/0 -> 5
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
   
  Background Routes From CBR/CDV Table
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  2 Routes To Node 2
      1. Hops 1. 1:ATM0/2 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
      2. Hops 1. 1:ATM0/1 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
   
  1 Routes To Node 5
      1. Hops 1. 1:ATM0/1 -> 5
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
  
  Background Routes From CBR/CTD Table
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 Routes To Node 2
      1. Hops 1. 1:ATM0/1 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
      2. Hops 1. 1:ATM0/1 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
   
  1 Routes To Node 5
      1. Hops 1. 1:ATM0/1 -> 5
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
  
  Background Routes From CBR/CTD Table
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  2 Routes To Node 2
      1. Hops 1. 1:ATM0/1 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
      2. Hops 1. 1:ATM0/2 -> 2
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
   
  1 Routes To Node 5
      1. Hops 1. 1:ATM0/1 -> 5
          ->: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10
          <-: aw 5040  cdv 138  ctd 154 acr 147743 clr0 10 clr01 10

Configuring Link Selection

The link selection feature allows you to choose the mode for selecting one specific link among several parallel links to the same neighbor node (for example, links between two adjacent switches).

When multiple parallel links are configured inconsistently, the order of precedence of configured values is as follows:

1. Admin-weight-minimize

2. Blocking-minimize

3. Transmit-speed-maximize

4. Load-balance

For example, if any link is configured as admin-weight minimize, that link is used for the entire link group.

To configure the PNNI link selection for, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
interface atm slot/port

Specify an ATM interface and enter interface configuration mode.

2
atm pnni link-selection {admin-weight-minimize | blocking-minimize | load-balance | transmit-speed-maximize}

Configure ATM PNNI link selection for a specific link.

Step	Command	Task
1	interface atm slot/port	Specify an ATM interface and enter interface configuration mode.
2	atm pnni link-selection {admin-weight-minimize \| blocking-minimize \| load-balance \| transmit-speed-maximize}	Configure ATM PNNI link selection for a specific link.

Example

This example shows how to configure ATM interface 0/0 to use the transmit-speed-maximize link selection mode and displays the result:

DSLAM(config)# interface atm 0/0
DSLAM(config-if)# atm pnni link-selection transmit-speed-maximize
DSLAM# show atm pnni neighbor
 
  Neighbor Name: eng_22, Node number: 2
  Neighbor Node Id: 56:160:47.0091810000000003DDE74601.0003DDE74601.00
  Neighboring Peer State: Full
  Link Selection Set To: minimize blocking of future calls
    Port          Remote port ID          Hello state
    ATM0/1        ATM1/2    (81902000)  2way_in 
    ATM0/2        ATM1/0    (81901000)  2way_in (Flooding Port)

Configuring the Maximum Administrative Weight Percentage

The maximum AW percentage feature allows you to prevent the use of alternate routes that consume too many network resources. This feature provides a generalized form of a hop count limit. The maximum acceptable administrative weight is equal to the specified percentage of the least administrative weight of any route to the destination (from the background routing tables). For example, if the least administrative weight to the destination is 5040 and the configured percentage is 300, the maximum acceptable administrative weight for the call is 5040 * 300 / 100 or 15120.

To configure the maximum AW percentage, perform these steps, beginning in global configuration mode:

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.
2	max-admin-weight-percentage percentage	Configure the maximum AW percentage. The value can range from 100 to 2000.

Note The max-admin-weight-percentage command takes effect only if background route computation is enabled.

Example

This example shows how to configure the node maximum AW percentage value as 300 and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# max-admin-weight-percentage 300
DSLAM# show atm pnni local-node
PNNI node 1 is enabled and running
  Node name: eng_1
  System address 47.009181000000000000001212.121212121212.00
  Node ID 56:160:47.009181000000000000001212.121212121212.00
  Peer group ID 56:47.0091.8100.0000.0000.0000.0000
  Level 56, Priority 0, No. of interface 4, No. of neighbor 1
 
  Hello interval 15 sec, inactivity factor 5, Hello hold-down 10 tenths of sec
  Ack-delay 2 sec, retransmit interval 10 sec, rm-poll interval 10 sec
  PTSE refresh interval 90 sec, lifetime factor 7, minPTSEinterval 1000 msec
  Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
  Default administrative weight mode: linespeed
     Max admin weight percentage: 300
  Next RM poll in 3 seconds

Configuring the Precedence

The route selection algorithm chooses routes to particular destinations using the longest match reachable address prefixes known to the DSLAM. When there are multiple longest match reachable address prefixes known to the DSLAM, the route selection algorithm first attempts to find routes to reachable addresses with types of greatest precedence. Among multiple longest match reachable address prefixes of the same type, routes with the least total AW are chosen first.

Local internal reachable addresses, whether learned through ILMI or as static routes, receive highest precedence or a precedence value of one. The precedence of other reachable address types is configurable.

To configure the precedence of reachable addresses, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
precedence [pnni-remote-exterior value_2-4 |
pnni-remote-exterior-metrics value_2-4 |
pnni-remote-internal value_2-4 |
pnni-remote-internal-metrics value_2-4 |
static-local-exterior value_2-4 |
static-local-exterior-metrics value_2-4 |
static-local-internal-metrics value_2-4]

At the configure ATM router prompt, enter PNNI precedence and configure the PNNI node.

Step	Command	Task
1	atm router pnni	At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#`.`
2	precedence [pnni-remote-exterior value_2-4 \| pnni-remote-exterior-metrics value_2-4 \| pnni-remote-internal value_2-4 \| pnni-remote-internal-metrics value_2-4 \| static-local-exterior value_2-4 \| static-local-exterior-metrics value_2-4 \| static-local-internal-metrics value_2-4]	At the configure ATM router prompt, enter PNNI precedence and configure the PNNI node.

Example

This example shows how to configure all PNNI remote exterior routes with a precedence value of 4 and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# precedence pnni-remote-exterior 4
DSLAM# show atm pnni precedence
                                 Working   Default
  Prefix Poa Type                Priority  Priority
  -----------------------------  --------  --------
  local-internal                    1         1
  static-local-internal-metrics     2         2
  static-local-exterior             3         3
  static-local-exterior-metrics     2         2
  pnni-remote-internal              2         2
  pnni-remote-internal-metrics      2         2
   pnni-remote-exterior              4         4
  pnni-remote-exterior-metrics      2         2

Tuning Topology Attributes

This section describes how to configure attributes that affect the network topology.

Configuring the Global Administrative Weight Mode

Administrative weight is the primary routing metric for minimizing use of network resources. You can configure the administrative weight (AW) to indicate the relative desirability of using a link. In addition to the per-interface atm pnni administrative-weight command, the ATM router PNNI administrative-weight command can be used to change the default AW assignment. For example, you can assign equal AWs to all links in the network to minimize the number of hops used by each connection.

To configure the administrative weight mode, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
administrative-weight {linespeed | uniform}

At the configure router prompt, configure the administrative weight for all node connections.

Figure 11-12 is an example of the effect of AW on call routing. The network depicted at the top of Figure 11-12 is configured as uniform, causing equal AW to be assigned to each link. The identical network at the bottom of the figure is configured as line speed.

The links between SW1 and SW2 (SW1p1 to SW2p1) and SW2 and SW3 (SW2p2 to SW3p2) are both faster OC-12 connections and have lower AWs. PNNI interprets the route over the two OC-12 links as being administratively equivalent to a more direct route between SW1 and SW3 using the OC-3 connection.

Figure 11-12: Network Administrative Weight Example

Example

This example shows how to configure AW for the node as line speed and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# administrative-weight linespeed
DSLAM# show atm pnni local-node
 
PNNI node 1 is enabled and running
  Node name: DSLAM
  System address 47.009181000000000000001212.121212121212.00
  Node ID 56:160:47.009181000000000000001212.121212121212.00
  Peer group ID 56:47.0091.8100.0000.0000.0000.0000
  Level 56, Priority 0, No. of interface 4, No. of neighbor 1
   Hello interval 15 sec, inactivity factor 5, Hello hold-down 10 tenths of sec
  Ack-delay 2 sec, retransmit interval 10 sec, rm-poll interval 10 sec
  PTSE refresh interval 90 sec, lifetime factor 7, minPTSEinterval 1000 msec
  Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
     Default administrative weight mode: linespeed
  Max admin weight percentage: 300
  Next RM poll in 3 seconds

Configuring Administrative Weight per Interface

AW is the main metric used for computation of the paths by PNNI. The assignment of AWs to links and nodes affects the way PNNI selects paths in the private ATM network.

To configure the administrative weight on an interface, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
interface atm slot/port

Specify an ATM interface and enter interface configuration mode.

2
atm pnni admin-weight number traffic_class

Configure the ATM AW for this link.

Example

This example shows how to configure ATM interface 0/0 with ATM PNNI AW of 7560 for traffic class ABR and displays the result:

DSLAM(config)# interface atm 0/0
DSLAM(config-if)# atm pnni admin-weight 7560 abr
DSLAM# show atm pnni interface atm 0/0 detail
 
Port ATM0/0 is up  , Hello state 2way_in with node eng_18 
    Next hello occurs in 11 seconds, Dead timer fires in 73 seconds
    CBR    : AW 5040 MCR 155519 ACR 147743 CTD 154 CDV 138 CLR0 10 CLR01 10 
    VBR-RT : AW 5040 MCR 155519 ACR 155519 CTD 707 CDV 691 CLR0 8 CLR01 8 
    VBR-NRT: AW 5040 MCR 155519 ACR 155519 CLR0 8 CLR01 8 
         ABR    : AW 7560 MCR 155519 ACR 0
    UBR    : AW 5040 MCR 155519 
    Remote node ID 56:160:47.00918100000000613E7B2F01.00613E7B2F99.00
    Remote node address 47.00918100000000613E7B2F01.00613E7B2F99.00
    Remote port ID  ATM0/1   (80102000) (0)

Configuring Transit Restriction

Transit calls originate from another ATM DSLAM and pass through the DSLAM. You may want to set your edge switches to eliminate this transit traffic and only allow traffic originating or terminating at the switch.

To configure a transit restriction, perform these steps, beginning in global configuration mode:

Example

This example shows how to enable the transit-restricted feature and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# node 1
DSLAM(config-pnni-node)# transit-restricted
DSLAM# show atm pnni local-node
  
   PNNI node 1 is enabled and running
    Node name: DSLAM
    System address 47.00918100000000400B0A3081.00400B0A3081.00
    Node ID 56:160:47.00918100000000400B0A3081.00400B0A3081.00
    Peer group ID 56:47.0091.8100.0000.0000.0000.0000
    Level 56, Priority 0, No. of interfaces 4, No. of neighbors 2
         Node Does Not Allow Transit Calls
 
    Hello interval 15 sec, inactivity factor 5,
    Hello hold-down 10 tenths of sec
    Ack-delay 10 tenths of sec, retransmit interval 5 sec,
    Resource poll interval 5 sec
    PTSE refresh interval 1800 sec, lifetime factor 200 percent,
    Min PTSE interval 10 tenths of sec
    Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
    Default administrative weight mode: uniform
    Max admin weight percentage: -1
    Next resource poll in 3 seconds
    Max PTSEs requested per PTSE request packet: 32
    Redistributing static routes: Yes

Configuring Redistribution

Redistribution instructs PNNI to distribute reachability information from non-PNNI sources throughout the PNNI routing domain. The DSLAM supports redistribution of static routes, such as those configured on IISP interfaces.

Note By default, redistribution of static routes is enabled.

To enable redistribution of static routes, perform these steps, beginning in global configuration mode:

Example

This example shows how to enable redistribution of static routes and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# node 1
DSLAM(config-pnni-node)# redistribute atm-static
DSLAM# show atm pnni local-node
  PNNI node 1 is enabled and running
    Node name: DSLAM
    System address 47.00918100000000400B0A3081.00400B0A3081.00
    Node ID 56:160:47.00918100000000400B0A3081.00400B0A3081.00
    Peer group ID 56:47.0091.8100.0000.0000.0000.0000
    Level 56, Priority 0, No. of interfaces 4, No. of neighbors 2
    Node Allows Transit Calls
 
    Hello interval 15 sec, inactivity factor 5,
    Hello hold-down 10 tenths of sec
    Ack-delay 10 tenths of sec, retransmit interval 5 sec,
    Resource poll interval 5 sec
    PTSE refresh interval 1800 sec, lifetime factor 200 percent,
    Min PTSE interval 10 tenths of sec
    Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
    Default administrative weight mode: uniform
    Max admin weight percentage: -1
    Next resource poll in 3 seconds
    Max PTSEs requested per PTSE request packet: 32
          Redistributing static routes: Yes

Configuring Aggregation Token

One of the tasks performed by the LGN is link aggregation. These terms describe the link aggregation algorithms:

An uplink is a link to a higher level node, called an upnode.
The term higher means at a higher level in the hierarchy compared to the level of our peer group.
The aggregation token controls the grouping of multiple physical links into logical links.
Uplinks to the same upnode, with the same aggregation token value, are represented at a higher level as horizontal aggregated links.
Resource Availability Information Groups (RAIGs) are computed according to the aggregation algorithm.

Figure 11-13 shows four physical links between four ATM switches. Two physical links between two ATM switches in different PGs are assigned the PNNI aggregation token value of 221; the other two are assigned the value of 100. These lines are summarized and represented in the next higher PNNI level.

Figure 11-13: PNNI Aggregation Token

When you configure the PNNI aggregation token

You only need to configure the interface on only one side of the link. If the configured aggregation token value of one side is zero and the other side is non-zero, the non-zero value is used by both sides as the aggregation token value.
If you choose to configure an aggregation token value on both interfaces, make sure the aggregation token values match. If the values do not match, the configuration is invalid and the default aggregation token value of zero is used.

To specify an aggregation token value, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
interface atm card/port

Specify the ATM interface.

2
atm pnni aggregation-token value

Enter a value for the aggregation-token on the ATM interface.

Example

This example shows how to configure an aggregation token on ATM interface 0/2 and displays the result (note that the show command includes the detail keyword):

DSLAM(config)# interface atm 0/2
DSLAM(config-if)# atm pnni aggregation-token 100
NewYork.BldB.T3 # show atm pnni interface atm0/2 detail
 
PNNI Interface(s) for local-node 1 (level=56):
 
Port ATM0/2 RCC is up  , Hello state common_out with node SanFran.BldA.T4 
  Next hello occurs in 4 seconds, Dead timer fires in 72 seconds
  CBR    : AW 5040 MCR 155519 ACR 147743 CTD 154 CDV 138 CLR0 10 CLR01 10 
  VBR-RT : AW 5040 MCR 155519 ACR 155519 CTD 707 CDV 691 CLR0 8 CLR01 8 
  VBR-NRT: AW 5040 MCR 155519 ACR 155519 CLR0 8 CLR01 8 
  ABR    : AW 5040 MCR 155519 ACR 0
  UBR    : AW 5040 MCR 155519 
  Aggregation Token: configured 0 , derived 2, remote 2
  Tx ULIA seq# 1, Rx ULIA seq# 1, Tx NHL seq# 1, Rx NHL seq# 2
  Remote node ID        72:160:47.009144556677223310111266.00603E7B2001.00
  Remote node address          47.009144556677223310111266.00603E7B2001.01
  Remote port ID         ATM0/0  (80003000) (0)
  Common peer group ID      56:47.0091.4455.6677.0000.0000.0000
  Upnode ID              56:72:47.009144556677223300000000.00603E7B2001.00
  Upnode Address               47.009144556677223310111266.00603E7B2001.02
  Upnode number: 11       Upnode Name: SanFran
NewYork.BldB.T3#

Configuring the Aggregation Mode

The DSLAM has two algorithms to perform link aggregation:

Best link—Selects a single optimal uplink, based on a selected parameter, and assigns the aggregated RAIG based on that uplink. With this aggregation algorithm, there is always a link that has the advertised RAIG parameters. The default aggregation mode is best link.
Aggressive—Examines each RAIG parameter and selects the best (optimal) value over all aggregated links. This procedure is repeated for each parameter. The resulting aggregated parameters reflect a best case that might not be represented by an existing uplink. Such an algorithm tends to attract calls towards the aggregated link. Because it might overestimate the available resources, it is termed aggressive.

All interfaces default to an aggregation token value of zero, so that by default all parallel outside links between a pair of peer groups are aggregated at higher levels. If the metrics of the various parallel outside links differ by very large ratios, you can improve the routing accuracy by assigning a different aggregation token to some links so that PNNI routing considers them separately at the higher levels.

To configure the aggregation mode for a traffic class, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

Enter ATM router PNNI mode from the terminal.

2
node node_index

Enter node configuration mode.

3
aggregation-mode {link} traffic-class {best-link | aggressive}

Configure the aggregation mode for a specific service category (traffic class).

Example

This example shows how to configure aggressive link aggregation mode for CBR traffic and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-pnni-node)# node 2
DSLAM(config-pnni-node)# aggregation-mode link cbr aggressive
DSLAM# show atm pnni aggregation link
 
PNNI PGL link aggregation for local-node 2 (level=72, name=DSLAM.2.72)
 
  Configured aggregation modes (per service class):
     CBR         VBR-RT       VBR-NRT       ABR           UBR
  ~~~~~~~~~~~  ~~~~~~~~~~~  ~~~~~~~~~~~  ~~~~~~~~~~~  ~~~~~~~~~~~
  aggressive   best-link    best-link    best-link    best-link
 
 No Aggregated links for this node.

Configuring Significant Change Thresholds

PNNI topology state packets (PTSEs) can overwhelm the network if they are transmitted each time a parameter in the network changes. To avoid this problem, PNNI uses significant change thresholds that control the origination of PTSEs.

Note Any change in AW and CLR is considered significant and triggers a new PTSE.

To configure the PTSE significant change threshold, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
node node_index

At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.

3
ptse significant-change
{acr-mtpercentage | acr-pmmultiplier |
cdv-pmmultiplier | ctd-pm multiplier}

Configure a PTSE significant change percentage or multiplier.

Example

This example shows how to configure a PTSE with a significant change percentage of 30, and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# node 1
DSLAM(config-pnni-node)# ptse significant-change acr-pm 30
DSLAM# show atm pnni resource-info
 
PNNI:80.1 Insignificant change parameters
acr pm 50,  acr mt 3, cdv pm 25, ctd pm 50, resource poll interval 5 sec
Interface insignificant change bounds:
Interface ATM0/1
  CBR    : MCR 155519, ACR 147743 [73871,366792], CTD 50 [25,75],CDV 34 [26,42],
 CLR0 10, CLR01 10,
  VBR-RT : MCR 155519, ACR 155519 [77759,366792], CTD 359 [180,538],CDV 342 [257
,427], CLR0 8, CLR01 8,
  VBR-NRT: MCR 155519, ACR 155519 [77759,155519], CLR0 8, CLR01, 8
  ABR    : MCR 155519 ACR 147743 [73871,155519]
  UBR    : MCR 155519
Interface ATM1/0
  CBR    : MCR 155519, ACR 147743 [73871,366792], CTD 50 [25,75],CDV 34 [26,42],
 CLR0 10, CLR01 10,
  VBR-RT : MCR 155519, ACR 155519 [77759,366792], CTD 359 [180,538],CDV 342 [257
,427], CLR0 8, CLR01 8,
  VBR-NRT: MCR 155519, ACR 155519 [77759,155519], CLR0 8, CLR01, 8
  ABR    : MCR 155519 ACR 147743 [73871,155519]
  UBR    : MCR 155519
<information deleted>

Tuning Protocol Parameters

This section describes how to tune the PNNI protocol parameters.

Configuring PNNI Hello, Database Synchronization, and Flooding Parameters

PNNI uses the Hello protocol to determine the status of neighbor nodes, and uses PTSEs to disseminate topology database information in the ATM network.

To configure the Hello protocol parameters and PTSE significant change, perform these steps, beginning in global configuration mode:

Step
Command
Task

1
atm router pnni

At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to DSLAM(config-atm-router)#.

2
node node_index

At the configure ATM router prompt, enter node configuration mode. The prompt changes to DSLAM(config-pnni-node)#.

3
timer [ack-delay tenths_of_seconds]
[hello-holddown tenths_of_seconds]
[hello-interval seconds]
[inactivity-factor number]
[retransmit-interval seconds]

Configure Hello database synchronization and flooding parameters.

4
ptse [lifetime-factor percentage_factor]
[min-ptse-interval tenths_of_seconds]
[refresh-interval seconds]
[request number]
[significant-change acr-mt percent]
[significant-change acr-pm percent]
[significant-change cdv-pm percent]
[significant-change ctd-pm percent]

Configure PTSE significant change percent number.

Example

This example shows how to configure the PTSE refresh interval to 600 seconds:

DSLAM(config-pnni-node)# ptse refresh-interval 600

This example shows how to configure the retransmission of the Hello timer to 60 seconds:

DSLAM(config-pnni-node)# timer hello-interval 60

This example shows the ATM PNNI Hello, database synchronization, and flooding configuration using the show atm pnni local-node privileged EXEC command:

DSLAM# show atm pnni local-node
PNNI node 1 is enabled and running
    Node name: DSLAM
    System address 47.00918100000000400B0A3081.00400B0A3081.00
    Node ID 56:160:47.00918100000000400B0A3081.00400B0A3081.00
    Peer group ID 56:47.0091.8100.0000.0000.0000.0000
    Level 56, Priority 0, No. of interfaces 4, No. of neighbors 2
    Node Allows Transit Calls
 
           Hello interval 60 sec, inactivity factor 5,
    Hello hold-down 10 tenths of sec
    Ack-delay 10 tenths of sec, retransmit interval 5 sec,
    Resource poll interval 5 sec
           PTSE refresh interval 600 sec, lifetime factor 200 percent,
    Min PTSE interval 10 tenths of sec
    Auto summarization: on, Supported PNNI versions: newest 1, oldest 1
    Default administrative weight mode: uniform
    Max admin weight percentage: -1
    Next resource poll in 3 seconds
    Max PTSEs requested per PTSE request packet: 32
    Redistributing static routes: Yes

Configuring the Resource Management Poll Interval

The resource management poll interval specifies the frequency with which PNNI polls resource management to update the values of link metrics and attributes. You can configure the resource poll interval to control the trade-off between the processing load and the accuracy of PNNI information. A larger value will probably generate a smaller number of PTSE updates. A smaller value results in greater accuracy in tracking resource information.

To configure the resource management poll interval, perform these steps, beginning in global configuration mode:

Example

This example configures the RM poll interval to 10 seconds and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# resource-poll-interval 10
DSLAM# show atm pnni resource-info
PNNI:80.1 Insignificant change parameters
acr pm 50,  acr mt 3, cdv pm 25, ctd pm 50, resource poll interval 10 sec
Interface insignificant change bounds:
Interface ATM0/1
  CBR    : MCR 155519, ACR 147743 [73871,366792], CTD 50 [25,75],CDV 34 [26,42],
 CLR0 10, CLR01 10,
  VBR-RT : MCR 155519, ACR 155519 [77759,366792], CTD 359 [180,538],CDV 342 [257
<information deleted>

Configuring Statistics Collection

This section describes how to collect statistics about the routing of ATM connections.

To enable statistics collection, perform these steps, beginning in global configuration mode:

Example

This example shows how to enable PNNI ATM statistics gathering and displays the result:

DSLAM(config)# atm router pnni
DSLAM(config-atm-router)# statistics call
DSLAM# show atm pnni statistics call
 
pnni call statistics since 22:19:29
 
                   total     cbr       rtvbr     nrtvbr    abr       ubr
source route reqs  1346      0         0         0         0         0       
successful         1342      1342      0         0         0         0       
unsuccessful       4         4         0         0         0         0       
crankback reqs     0         0         0         0         0         0       
successful         0         0         0         0         0         0       
unsuccessful       0         0         0         0         0         0       
on-demand attempts 0         0         0         0         0         0       
successful         0         0         0         0         0         0       
unsuccessful       0         0         0         0         0         0       
background lookups 0         0         0         0         0         0       
successful         0         0         0         0         0         0       
unsuccessful       0         0         0         0         0         0       
next port requests 0         0         0         0         0         0       
successful         0         0         0         0         0         0       
unsuccessful       0         0         0         0         0         0       
 
                   total     average
usecs in queue     2513166   1867    
usecs in dijkstra  0         0       
usecs in routing   132703    98

Step	Command	Task
1	interface atm card/port	Specify the ATM interface.
2	atm pnni aggregation-token value	Enter a value for the aggregation-token on the ATM interface.

Table of Contents

Configuring ATM Routing and PNNI

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Switch NewYork.BldB.T1 Configuration

Switch NewYork.BldB.T2 Configuration

Switch NewYork.BldB.T3 Configuration

Switch SanFran.BldA.T4 Configuration

Switch SanFran.BldA.T5 Configuration

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