|
|
This chapter describes the Interim Interswitch Signaling Protocol (IISP) and Private Network-Network Interface (PNNI) ATM routing protocol implementations on the ATM switch. This chapter includes the following sections:
To place calls between ATM end systems, signalling consults an either IISP, a static routing protocol, or PNNI, a dynamic routing protocol that provides quality of service (QoS) routes to signalling based on the QoS requirements specified in the call setup request.
This section provides an overview of PNNI with a comparison to IISP, and includes the following subsections:
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.
In a PNNI routing domain, the source ATM switch computes hierarchically complete routes for connection setups. This route information is included in the call setup signalling message.
In contrast, IISP uses hop-by-hop routing, where each ATM switch 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.
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 the available cell rate (AvCR), maximum cell transfer delay (maxCTD), peak-to-peak cell delay variation (CDV), and 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.
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 ATM switches outside of the peer group.
The key components of the PNNI hierarchy follow:
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 section "Configuring the Lowest Level of the PNNI Hierarchy" later in this chapter 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 section "Configuring Higher Levels of the PNNI Hierarchy" later in this chapter for more information.
Figure 10-1 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 10-2 shows a PNNI hierarchical network topology. In a PNNI hierarchical network, the number of nodes, links, and reachable address prefixes visible from any one ATM switch in the network are reduced exponentially as the flat network is migrated to a hierarchical network.
PNNI hierarchy has some 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 ATM switch in the network. These reductions improve the effectiveness of your network by reducing the control traffic, memory, and processing required by each ATM 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 many factors, including the size of the network, type of network traffic, call setup activity, and 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 can be a strong indication that a hierarchical organization of the topology is needed.
This section describes ATM addresses and includes the following subsections:
The ATM switch comes 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 ATM switch.
The preconfigured ATM address format provided by Cisco Systems is shown in Figure 10-3. All preconfigured addresses share the same seven-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 ATM switches, one large autoconfigured peer group is created at level 56. The next six bytes comprise the MAC address of the ATM switch. The 7-byte address prefix combined with the 6-byte MAC address provide a 13-byte prefix that uniquely identifies each ATM switch. This 13-byte prefix is also the default ILMI address prefix and is used by ILMI for address registration and summarization.
The address format used in PNNI is called the ATM End System Address (AESA). AESAs are 20 octets and are derived from the ISO definition of NSAPs. AESAs can be further classified based on the first octet, called the Authority and Format Identifier (AFI). The ATM Forum specifications through UNI 4.0 only specify 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 ATM switch does not restrict the AFI values.
The other address format used in ATM is E.164 numbers, also known as native E.164 numbers. 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. Refer to the next section "E.164 AESA Prefixes" for more information about using E.164 AESAs with PNNI.
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 using native E.164 numbers with E.164 AESAs.
The encoding defined for E.164 AESAs in the ATM Forum UNI specifications is shown in Figure 10-4.
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, you would configure static routes to the following set of E.164 AESA prefixes:
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 10-5.
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.
The ATM switch 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 ATM switch automatically (that is, representing the ATM switch address and the soft PVC addresses on this ATM 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.
To create private ATM networks that can interoperate with a global ATM internetwork, all ATM addresses should be globally unique. For scalability reasons, we also recommend that addresses align with the network topology (see the section "Designing an ATM Address Plan").
To satisfy the uniqueness requirement and facilitate distribution, a number of registration authorities administer ATM addresses. These addresses are usually distributed in sets of addresses having a common prefix. The uniqueness of the prefix, which is used to define a group of addresses, is ensured by the registration authority. The recipient allocates the remaining part of the ATM address to devise an addressing scheme that is appropriate for the private network. The recipient has to assign the remaining address part in a way that creates a set of unique addresses. If these guidelines are followed, private ATM networks can achieve global ATM interconnection without the need to renumber the addressing scheme. At the end of this section are some references that contain information on how to obtain a globally unique ATM prefix.
AESA prefixes are differentiated by ownership, as follows:
If you have a private network, you can obtain ATM prefixes from the following:
A customer owned ATM address (assigned by Cisco) is preconfigured on every ATM switch. If you are not implementing hierarchy in your PNNI network and do not plan to interconnect to a global ATM internetwork, you can use the preconfigured ATM address.
ATM service providers can obtain the following types of ATM addresses:
A good source for an ICD ATM prefix is the IOTA scheme administered by BSI. It is preferable to US DCC AESAs. The documentation on how to get an organizational identifier and how to construct a AESA from the organizational identifier is also easier to follow for IOTA than that for US DCC AESAs. For more information, see http://www.bsi.org.uk/disc/iota.html.
The following additional publications can also provide guidance on how to obtain a globally unique ATM prefix:
Your ATM address plan is key to efficient operation and management of PNNI networks. When designing an ATM address plan, the three most important things to remember are:
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 10-6.
For more information, refer to the section "Obtaining ATM Addresses," earlier in this chapter.
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. The assigned address space can be further subdivided by providing longer prefixes to different regions of the network. Within each peer group, the first level bits of each ATM switch address should match the corresponding bits of the Peer Group Identifier (PGI) value. An example of a hierarchical address assignment is shown in Figure 10-7.
Note that the address prefix is longer at each lower level of the PNNI hierarchy shown in Figure 10-7.
The advantages of hierarchical address assignment include:
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).
When 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 (see the appendix "PNNI Migration Examples").
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 10-8).
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 would share a common 12th octet, leaving the 13th octet for downward future expansion. The octet pairs (12 and 13) for these switches could be as follows: (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 will be able to accommodate up to 65,536 switches in the same region. An example of HO-DSP assignment is shown in Figure 10-9.
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.
This section describes the procedures necessary for IISP configuration, and includes the following subsections:
The ATM routing software can be restricted to operate in static mode. In this mode, the 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 is configured using static routing mode on each interface, the switch ILMI variable atmfAtmLayerNniSigVersion is set to IISP. This causes either of the following to happen:
To configure the routing mode, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Configure the ATM routing mode to static. | |
| 2 | end | Exit configuration mode. |
| 3 | copy system:running-config nvram:startup-config | Write the running configuration to the startup configuration. |
| 4 | reload | Reload the switch software. |
The following example shows how to use the atm routing-mode static command to restrict the switch operation to static routing mode:
Switch(config)# atm routing-mode static This Configuration Will Not Take Effect Until Next Reload. Switch(config)# end Switch# copy system:running-config nvram:startup-config Building configuration... [OK] Switch# reload
The following example shows how to reset the switch operation back to PNNI if the switch is operating in static mode:
Switch(config)# no atm routing-mode static This Configuration Will Not Take Effect Until Next Reload. Switch(config)# end Switch# copy system:running-config nvram:startup-config Building configuration... [OK] Switch# reload
To display the ATM routing mode configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
more system:running-config | Display the ATM routing mode configuration. |
The following example shows the ATM routing mode configuration using the more system:running-config privileged EXEC command:
Switch# more system:running-config Building configuration... Current configuration: ! version 11.2 no service pad service udp-small-servers service tcp-small-servers ! hostname Switch ! ! 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 CBR0/0/0 no ip address <information deleted>
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.
To change the active ATM address, create a new address, verify that it exists, and then delete the current active address, follow these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | atm address address-template | Configure the ATM address for the switch. |
| 2 | end | Return to privileged EXEC mode. |
| 3 | Verify the new address. | |
| 4 | configure terminal | Enter configuration mode from the terminal. |
| 5 | no atm address address-template | At the configuration mode prompt, remove the old ATM address from the switch. |
The following example shows how to add the ATM address prefix 47.0091.8100.5670.000.0ca7.ce01. Using the ellipses (...) adds the default Media Access Control (MAC) address as the last six bytes.
Switch(config)# atm address 47.0091.8100.5670.0000.0ca7.ce01... Switch(config)# no atm address 47.0091.8100.0000.0041.0b0a.1081...
To display the ATM address configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the ATM address configuration. |
The following example shows the ATM address configuration using the show atm addresses EXEC command:
Switch# show atm addresses Switch Address(es):
47.00918100000000410B0A1081.00410B0A1081.00 active 47.00918100567000000CA7CE01.00410B0A1081.00 Soft VC Address(es): 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.0000.00 ATM0/0/0 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.0000.63 ATM0/0/0.99 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.0010.00 ATM0/0/1 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.0020.00 ATM0/0/2 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.0030.00 ATM0/0/3 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.1000.00 ATM0/1/0 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.1010.00 ATM0/1/1 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.1020.00 ATM0/1/2 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.1030.00 ATM0/1/3 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.8000.00 ATM1/0/0 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.8010.00 ATM1/0/1 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.8020.00 ATM1/0/2 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.8030.00 ATM1/0/3 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.9000.00 ATM1/1/0 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.9010.00 ATM1/1/1 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.9020.00 ATM1/1/2 47.0091.8100.0000.0041.0b0a.1081.4000.0c80.9030.00 ATM1/1/3 ILMI Switch Prefix(es): 47.0091.8100.0000.0041.0b0a.1081 47.0091.8100.0000.0060.3e5a.db01 ILMI Configured Interface Prefix(es): LECS Address(es):
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.
To configure a static route, use the following global configuration command:
| Command | Task |
|---|---|
atm route addr-prefix atm card/subcard/port | Specify a static route to a reachable address prefix. |
The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0:
Switch(config)# atm route 47.0091.8100.0000.0041.0B0A.1081 atm 0/0/0
The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0 configured with a scope 1 associated:
Switch(config)# atm route 47.0091.8100.0000.0041.0B0A.1081 atm 0/0/0 scope 1
To display the ATM static route configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the static route configuration. |
The following example shows the ATM static route configuration using the show atm route EXEC command:
Switch# 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 ATM0/0/0 DN 56 47.0091.8100.0000/56
S E 1 ATM0/0/0 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 UP 0 47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081/152
R I 1 ATM0 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 UP 0 47.0091.8100.5670.0000.0000.0000.0040.0b0a.1081/152
R I 1 ATM0 UP 0 47.0091.8100.5670.0000.0000.0000.4000.0c/128
This section describes all the procedures necessary for a basic PNNI configuration and includes the following subsections:
The ATM switch defaults to a working PNNI configuration suitable for operation in isolated flat topology ATM networks. The switch comes with a globally unique preconfigured ATM address. Manual configuration is not required if you:
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 section "Configuring Higher Levels of the PNNI Hierarchy" later in this chapter.
The lowest level PNNI configuration includes the following procedures:
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.
If you are planning to implement PNNI hierarchy, follow the procedure in this section to configure an ATM address and the PNNI node level.
The ATM switch is preconfigured as a single lowest-level PNNI node (locally identified as node 1) with a level of 56. The node ID and peer group ID are calculated 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. 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 10-7 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 Node IDs and peer group IDs are not recalculated until the node is disabled and then reenabled. |
To change the active ATM address, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | atm address address-template | At the configuration mode prompt, configure the new ATM address for the switch. |
| 2 | end | Return to privileged EXEC mode. |
| 3 | Verify the new address. | |
| 4 | configure terminal | Enter configuration mode from the terminal. |
| 5 | no atm address address-template | At the configuration mode prompt, remove the old ATM address from the switch. |
| 6 | At the configuration mode prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)#. | |
| 7 | At the configure ATM router prompt, disable the PNNI node. | |
| 8 | node 1 level level-indicator enable | Reenable the node. You can also change the node level if required for your configuration. |
The following example changes the ATM address of the switch 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:
Switch(config)# atm address 47.0091.8100.5670.0000.0000.1122... Switch(config)# no atm address 47.0091.8100.0000.0041.0b0a.1081... Switch(config)# atm router pnni Switch(config-atm-router)# node 1 disable Switch(config-pnni-node)# node 1 enable
To display the ATM PNNI node configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the ATM PNNI node configuration. |
The following example shows the PNNI node configuration using the show atm pnni local-node privileged EXEC command:
Switch# 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
Because PNNI is a dynamic routing protocol, static routes are not necessary between nodes that support PNNI. However, you can extend the routing capability of PNNI beyond nodes that support PNNI to:
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.
To configure a static route connection, use the following global configuration command:
| Command | Task |
|---|---|
atm route addr-prefix atm card/subcard/port | Specify a static route to a reachable address prefix. |
The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0:
Switch(config)# atm route 47.0091.8100.0000.0041.0B0A.1081 atm 0/0/0
The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0 configured with a scope 1 associated:
Switch(config)# atm route 47.0091.8100.0000.0041.0B0A.1081 atm 0/0/0 scope 1
To display the ATM static route configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the static route configuration. |
The following example shows the ATM static route configuration using the show atm route EXEC command:
Switch# 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 ATM0/0/0 DN 56 47.0091.8100.0000/56
S E 1 ATM0/0/0 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 UP 0 47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081/152
R I 1 ATM0 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 UP 0 47.0091.8100.5670.0000.0000.0000.0040.0b0a.1081/152
R I 1 ATM0 UP 0 47.0091.8100.5670.0000.0000.0000.4000.0c/128
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 switch. This address prefix is advertised into its peer group.
You can configure multiple addresses for a single switch 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.
To configure a summary address, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)#. | |
| 2 | node node_index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)#. |
| 3 | no auto-summary | Remove the default summary address(es). |
| 4 | summary-address address-prefix | Configure the ATM PNNI summary address prefix. |
The following example shows how to remove the default summary address(es) and add summary address 47.009181005670:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# no auto-summary Switch(config-pnni-node)# summary-address 47.009181005670
To display the ATM PNNI summary address configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display a summary of the PNNI hierarchy. |
The following example shows the ATM PNNI summary address configuration using the show atm pnni summary privileged EXEC command:
Switch# 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
The PNNI address scope allows you to restrict advertised reachability information within configurable boundaries.
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, whenever the level of node 1 is modified, the scope map should be reconfigured to avoid unintended suppression of reachability advertisements. Misconfiguration of the scope map might cause addresses to remain unadvertised.
In automatic mode, the UNI to PNNI level mapping is automatically reconfigured whenever the level of the node 1 is modified. The automatic reconfiguration avoids misconfigurations caused by node level modifications. Automatic adjustment of scope mapping uses the values shown in Table 10-1.
| 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 |
Entering the scope mode automatic command 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node-index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(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. |
| 1You must enter the scope mode manual command to allow scope mapping configuration. |
The following example shows how to configure PNNI scope mapping manually so that organizational scope values 1 through 8 map to PNNI level 72:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# scope mode manual Switch(config-pnni-node)# scope map 1 8 level 72
To display the PNNI scope mapping configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the node PNNI scope mapping configuration. |
The following example shows the ATM PNNI scope mapping configuration using the show atm pnni scope privileged EXEC command:
Switch# show atm pnni scope UNI scope PNNI Level ~~~~~~~~~ ~~~~~~~~~~ (1 - 10) 56 (11 - 12) 48 (13 - 14) 32 (15 - 15) 0 Scope mode: manual
This section describes the procedures to configure higher levels of PNNI hierarchy, and includes the following procedures:
A PNNI hierarchy configuration example follows these procedures. PNNI hierarchy migration examples are described in the appendix "PNNI Migration Examples."
After you have configured the lowest level of the PNNI hierarchy (see the section "Configuring the Lowest Level of the PNNI Hierarchy"), 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 10-10 shows an example of PGLs and LGNs.
To create the PNNI hierarchy, select switches 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.
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 switch creates additional PNNI processing and results in slower recovery from failures. Selecting switches for election with more processing capability (for example, because a smaller volume of call processing compared to others) may be better.
We recommend that every node in a peer group that can become a PGL have the same parent node configuration.
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 switch (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 will only become active if:
To configure a LGN and peer group identifier, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Enter ATM router PNNI mode. The prompt changes to Switch(config-atm-router)#. | |
| 2 | node node-index level level-indicator [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 switch, you must specify a different index number to distinguish it from node 1. |
The following example shows how to create a new node 2 with a level of 56 and a peer group identifier of 56:47009111223344:
Switch(config)# atm router pnni Switch(config-atm-router)# node 2 level 56 peer-group-identifier 56:47009111223344 enable Switch(config-pnni-node)# end
Notice that the PNNI level and the first two digits of the peer group identifier are the same.
To display the LGN configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the PNNI node information. |
The following example shows the PNNI node information using the show atm pnni local-node privileged EXEC command:
Switch# 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
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. We recommend you chose a node name of 12 characters or less so that your screen displays remain nicely formatted and easy to read.
After a node name has been configured, it is distributed 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node-index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)#. |
| 3 | name name | Configure the node name. |
Configure the name of the node as eng_1 using the name command, as in the following example:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# name eng_1
To display the ATM PNNI node name configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the ATM PNNI router configuration. |
This example shows how to display the ATM node name configuration using the show atm pnni local-node command from user EXEC mode:
Switch# 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
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 next section "Configure the Node Election Leadership Priority"). 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node_index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)# |
| 3 | parent node_index | Configure the parent node index. |
The following example shows how to create a parent node for node 1:
Switch(config)# atm router pnni Switch(config-pnni-node)# node 1 Switch(config-pnni-node)# parent 2
To display the parent node configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the PNNI hierarchy. |
The following example shows the ATM parent node information using the show atm pnni hierarchy privileged EXEC command:
Switch# show atm pnni hierarchy Locally configured parent nodes: Node Parent Index Level Index Local-node Status Node Name ~~~~~ ~~~~~ ~~~~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~ 1 80 2 Enabled/ Running Switch 2 72 N/A Enabled/ Running Switch.2.72
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 the configured priority must be 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.
The control for election is done through the assignment of leadership priorities. We recommend that the leadership priority space be divided into three tiers:
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.
Nodes that you do not want to become PGLs should remain with the 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 will remain PGL until it goes down or is configured to step down.
If certain nodes should 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 this 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.
To configure the election leadership priority, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | 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. |
The following example shows how to change the election leadership priority for node 1 to 100:
Switch(config)# atm router pnni Switch(config-pnni-node)# node 1 Switch(config-pnni-node)# election leadership-priority 100
To display the node election leadership priority, use one of the following privileged EXEC commands:
| Command | Task |
|---|---|
Display the node election leadership priority. | |
Display all nodes in the peer group. |
The following example shows the election leadership priority using the show atm pnni election privileged EXEC command:
Switch# 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
The following example shows all nodes in the peer group using the show atm pnni election peers command:
Switch# 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
Summary addresses can be used 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. Summary addresses should only be used 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.
A single default summary address is configured 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.
Summary addresses other than defaults must be explicitly configured on each node. Use the summary-address command to manually configure summary address prefixes. A node can have multiple summary address prefixes.
Note that every node in a peer group that has a potential to become a PGL should have the same summary address lists in its parent node configuration.
To configure the ATM PNNI summary address prefix, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)#. | |
| 2 | node node_index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)#. |
| 3 | no auto-summary | Remove the default summary address(es). |
| 4 | summary-address address-prefix | Configure the ATM PNNI summary address prefix. |
The following example shows how to remove the default summary address(es) and add summary address 47.009181005670:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# no auto-summary Switch(config-pnni-node)# summary-address 47.009181005670
To display the ATM PNNI summary address configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the ATM PNNI summary address configuration. |
The following example shows the ATM PNNI summary address configuration using the show atm pnni summary privileged EXEC command:
Switch# 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
An example configuration for a three-level hierarchical topology is shown in Figure 10-11. The example shows the configuration of only five switches, although there can be many other switches in each peer group.
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 that have been induced through level 64 form an aggregated horizontal link within the common peer group at level 56.
The sections that follow show the configurations for each switch and the outputs of the show atm pnni local-node command. Some of the output text has been suppressed because it is not relevant to the example.
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>
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>
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>
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>
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>
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 tune your network performance. This section includes the following subsections:
The tasks described in the following sections are used to tune the route selection in your PNNI network:
The ATM switch supports the following two route selection modes:
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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | background-routes-enable | Enable background routes and configure background route parameters. |
The following example shows how to enable background routes and configures the background routes poll interval to 30 seconds:
Switch(config)# atm router pnni Switch(config-atm-router)# background-routes-enable poll-interval 30
To display the background route configuration, use the following privileged EXEC commands:
| Command | Task |
|---|---|
Display the background route configuration. | |
Display background routing tables. |
The following example shows the ATM PNNI background route configuration using the show atm pnni background status privileged EXEC command:
Switch# show atm pnni background status Background Route Computation is Enabled Background Interval is set at 10 seconds Background Insignificant Threshold is set at 32
The following example shows the ATM PNNI background route tables for CBR using the show atm pnni background routes privileged EXEC command:
Switch# show atm pnni background routes cbr
Background Routes From CBR/AW Table
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 Routes To Node 2
1. Hops 1. 1:ATM0/1/2 -> 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:ATM0/1/1 -> 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:ATM0/1/0 -> 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:ATM0/1/2 -> 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:ATM0/1/1 -> 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:ATM0/1/0 -> 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/CTD Table
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 Routes To Node 2
1. Hops 1. 1:ATM0/1/2 -> 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:ATM0/1/1 -> 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:ATM0/1/0 -> 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/CTD Table
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 Routes To Node 2
1. Hops 1. 1:ATM0/1/2 -> 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:ATM0/1/1 -> 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:ATM0/1/0 -> 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
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 card/subcard/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. |
The following example shows how to configure ATM interface 0/0/0 to use the transmit-speed-maximize link selection mode:
Switch(config)# interface atm 0/0/0 Switch(config-if)# atm pnni link-selection transmit-speed-maximize
To display the ATM PNNI link selection configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the ATM PNNI link selection configuration. |
The following example shows the detailed PNNI link selection configuration using the show atm pnni neighbor EXEC command:
Switch# 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
ATM0/1/2 ATM3/1/2 (81902000) 2way_in
ATM0/1/1 ATM3/1/1 (81901000) 2way_in (Flooding Port)
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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)#. | |
| 2 | max-admin-weight-percentage percentage | Configure the maximum AW percentage. The value can range from 100 to 2000. |
The following example shows how to configure the node maximum AW percentage value as 300:
Switch(config)# atm router pnni Switch(config-atm-router)# max-admin-weight-percentage 300
To display the node ATM PNNI maximum AW percentage configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the node ATM PNNI maximum AW configuration. |
The following example shows the maximum AW percentage configuration using the show atm pnni local-node privileged EXEC command:
Switch# 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
The route selection algorithm chooses routes to particular destinations using the longest match reachable address prefixes known to the switch. When there are multiple longest match reachable address prefixes known to the switch, 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 via ILMI or as static routes, are given 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | precedence [pnni-remote-exterior value | | At the configure ATM router prompt, enter PNNI precedence and configure the PNNI node. |
The following example shows how to configure all PNNI remote exterior routes with a precedence value of 4:
Switch(config)# atm router pnni Switch(config-atm-router)# precedence pnni-remote-exterior 4
To display the ATM PNNI route determination precedence configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the node ATM PNNI route determination precedence configuration. |
The following example shows the ATM PNNI route determination precedence configuration using the show atm pnni precedence privileged EXEC command:
Switch# 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
The tasks in the following sections describe how to configure attributes that affect the network topology:
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, assigning equal AWs to all links in the network will 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | administrative-weight {linespeed | uniform} | At the configure router prompt, configure the administrative weight for all node connections. |
Figure 10-12 is an example of how AW affects call routing. The network depicted at the top of Figure 10-12 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 linespeed. 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.
The following example shows how to configure AW for the node as line speed:
Switch(config)# atm router pnni Switch(config-atm-router)# administrative-weight linespeed
To display the AW configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the AW configuration for the node. |
The following example shows the AW configuration for the node using the show atm pnni local-node privileged EXEC command:
Switch# show atm pnni local-node PNNI node 1 is enabled and running Node name: switch 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
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 card/subcard/port | Specify an ATM interface and enter interface configuration mode. |
| 2 | atm pnni admin-weight number service-category | Configure the ATM AW for this link. |
The following example shows how to configure ATM interface 0/0/0 with ATM PNNI AW of 7560 for traffic class ABR:
Switch(config)# interface atm 0/0/0 Switch(config-if)# atm pnni admin-weight 7560 abr
To display the ATM PNNI interface AW configuration, use the following EXEC command:
| Command | Task |
|---|---|
show atm pnni [interface atm card/subcard/port] [detail] | Display the interface ATM PNNI AW configuration. |
The following example shows the AW configuration for interface 0/0/0 using the show atm pnni interface EXEC command:
Switch# show atm pnni interface atm 0/0/0 detail
Port ATM0/0/0 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 5040 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 ATM0/1/2 (80102000) (0)
Transit calls originate from another ATM switch and pass through the switch. Some edge switches might want 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:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node-index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)#. |
| 3 | Enable transit restricted on this node. |
The following example shows how to enable the transit-restricted feature:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# transit-restricted
To display the ATM PNNI transit-restriction configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the ATM configuration. |
The following example shows the ATM PNNI transit-restriction configuration using the show atm pnni local-node privileged EXEC command:
Switch# show atm pnni local-node
PNNI node 1 is enabled and running
Node name: Switch
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
Redistribution instructs PNNI to distribute reachability information from non-PNNI sources throughout the PNNI routing domain. The ATM switch supports redistribution of static routes, such as those configured on IISP interfaces.
To enable redistribution of static routes, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node-index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)# |
| 3 | Enable redistribution of static routes. |
The following example shows how to enable redistribution of static routes:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# redistribute atm-static
To display the node redistribution configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the node redistribution configuration. |
The following example shows the node redistribution configuration using the show atm pnni local-node privileged EXEC command:
Switch# show atm pnni local-node
PNNI node 1 is enabled and running
Node name: Switch
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
One of the tasks performed by the LGN is link aggregation. To describe the link aggregation algorithms we need to introduce the terms of upnodes, uplinks and aggregated links. 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 10-13 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.
When configuring the PNNI aggregation token:
To specify an aggregation token value, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | interface atm card/subcard/port | Specify the ATM interface. |
| 2 | Enter a value for the aggregation-token on the ATM interface. |
The following example shows how to configure an aggregation token on ATM interface 1/0/1:
Switch(config)# interface atm 1/0/1 Switch(config-if)# atm pnni aggregation-token 100
To display the aggregation token configuration, use the following EXEC command:
| Command | Task |
|---|---|
show atm pnni interface atm card/subcard/port [detail] | Display the interface PNNI configuration. |
The following example shows the aggregation token value for all interfaces using the show atm pnni interface EXEC command:
NewYork.BldB.T3# show atm pnni interface PNNI Interface(s) for local-node 1 (level=56): Local Port Type RCC Hello St Deriv Agg Remote Port Rem Node(No./Name) ~~~~~~~~~~~~~ ~~~~~ ~~~ ~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~ ATM0/0/2 Phy UP comm_out 2 ATM0/0/3 - SanFran.BldA.T4 ATM0/1/2 Phy DN down 35 ATM0/1/3 Phy UP 2way_in 0 ATM1/1/3 10 NewYork.BldB.T1 NewYork.BldB.T3#
The following example shows the aggregation token value details for a specific interface using the show atm pnni interface EXEC command with the detail keyword:
NewYork.BldB.T3 # show atm pnni interface atm 0/0/2 detail PNNI Interface(s) for local-node 1 (level=56): Port ATM0/0/2 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 ATM0/0/3 (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#
You configure the aggregation mode for calculating metrics and attributes for aggregated PNNI links and nodes advertised to higher PNNI levels. The ATM switch has two algorithms to perform link and node aggregation: best link and aggressive.
To specify the mode that is used to calculate the combined metrics from multiple lower-level PNNI links into individual aggregated links to be advertised by this node, use the aggregation-mode link command.
The best link algorithm 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.
The aggressive aggregation algorithm examines each RAIG parameter and selects the best (optimal) value over all aggregated links. This procedure is repeated for each parameter individually. The resulting aggregated parameters reflect a best case that might not be represented by an existing uplink. Since this algorithm tends to attract calls towards the aggregated link, it is called aggressive.
To specify the mode that is used to calculate the combined path metrics between pairs of lower-level border nodes to be advertised by the complex node, use the aggregation-mode node command.
The best-link aggregation algorithm selects the radius, spoke, and bypass paths based on a single calculation between each pair of border nodes, which optimizes a single parameter:
The aggressive algorithm selects the radius, spoke, and bypass paths based on the best values from two path calculations for each pair of border nodes, which optimize different parameters:
To configure link or node aggregation, perform the following steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Enter ATM router PNNI mode. | |
| 2 | node node-index | Enter node configuration mode and specify the local node you want to configure. |
| 3 | aggregation-mode {link | node} {abr | cbr | ubr | vbr-rt | vbr-nrt | all} {best-link | aggressive} | Configure the service category and aggregation mode for a link or a complex node. |
The following example shows how to configure aggressive link aggregation mode for CBR traffic:
Switch(config)# atm router pnni Switch(config-pnni-node)# node 2 Switch(config-pnni-node)# aggregation-mode link cbr aggressive
The following example shows how to configure best link aggregation mode for VBR-RT traffic on node 2:
Switch(config)# atm router pnni Switch(config-pnni-node)# node 2 Switch(config-pnni-node)# aggregation-mode node vbr-rt best-link
To display the aggregation mode configuration, enter the following commands in EXEC mode:
| Command | Task |
|---|---|
Display the link aggregation mode. | |
Display the node aggregation mode. |
The following example shows the link aggregation mode:
Switch# show atm pnni aggregation link
PNNI PGL link aggregation for local-node 2 (level=72, name=Switch.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.
Switch#
The following example shows how to display the node aggregation mode:
Switch# show atm pnni aggregation node
PNNI nodal aggregation for local-node 2 (level=56, child PG level=60)
Complex node representation, exception threshold: 60%
Configured nodal aggregation modes (per service class):
CBR VBR-RT VBR-NRT ABR UBR
~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~
best-link best-link best-link best-link aggressive
Summary Complex Node Port List:
Port ID Rem Inn Agg-Token Border Cnt In-Spoke Out-Spoke Agg-Accur
~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~
21FB000 12 0 1 default default ok
2371000 13 0 1 default default ok
Summary Complex Node Bypass Pairs List (exception bypass pairs only)
/~~~~~~~~ LOWER PORT ID ~~~~~~~~\ /~~~~~~~~ HIGHER PORT ID ~~~~~~~\
Port ID Rem Inn Agg-Token Inacc Port ID Rem Inn Agg-Token Inacc Exceptns
~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~ ~~~~~~~~
21FB000 12 0 no 2371000 13 0 no fwd rev
PTSEs would overwhelm the network if they were transmitted every time any parameter in the network changed. To avoid this problem, PNNI uses significant change thresholds that control the origination of PTSEs.
To configure the PTSE significant change threshold, take these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)#. | |
| 2 | node node_index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)#. |
| 3 | ptse significant-change | Configure a PTSE significant change percentage. |
For an example of other ptse command keywords, see the section "Configure PNNI Hello, Database Synchronization, and Flooding Parameters."
The following example shows how to configure a PTSE being sent only if the available cell rate changes 30 percent from the current metric:
Switch(config)# atm router pnni Switch(config-atm-router)# node 1 Switch(config-pnni-node)# ptse significant-change acr-pm 30
To display the PTSE configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the PTSE identifier. |
The following example shows the significant change threshold configuration using the show atm pnni resource-info EXEC command:
Switch# 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 ATM1/0/0 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 Interface ATM1/0/3 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>
By default, higher-level LGNs represent their child PGs in the simple node representation. With simple node representation, the entire PG is represented as a single node. When there are many nodes in the child PG, you can use complex node representation to present a more accurate model of the PG. With complex node representation, the PG is represented by a nucleus, or center, and border ports.
In the simplest radius-only version, a single set of radius metrics are advertised, which represent an average path to the nucleus of the PG. Paths that traverse the PG are represented as a first hop from the entry port to the nucleus and a second hop from the nucleus to the exit port, both of which use radius metrics.
You can also specify an exception threshold. If any port has paths to other ports or to the nucleus that differ by more than the threshold percentage from the default radius metrics, they are advertised automatically as sets of exception metrics.
Exceptions between two ports are referred to as bypass exceptions, whereas exceptions between a port and the nucleus are referred to as spoke exceptions. By decreasing the exception threshold, the accuracy of the complex node representation is improved by advertising additional spokes and bypasses as exceptions.
Figure 13-1 illustrates an example of a PNNI complex node representation.
To configure complex node representation, perform the following steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Enter ATM router PNNI mode. | |
| 2 | node local-node-index | Enter node configuration mode and specify the local node you want to configure. |
| 3 | nodal-representation {simple | complex [threshold threshold-value | radius-only]} | Configure complex nodal representation and specify how to handle exceptions. |
The following example shows how to configure a PNNI complex node:
Switch(config)# atm router pnni Switch(config-atm-router)# node 2 Switch(config-pnni-node)# nodal-representation complex
To display the PNNI complex node configuration, perform the following task in privileged EXEC mode:
| Command | Task |
Display the PNNI complex node configuration. |
The following example shows the PNNI complex node configuration:
Switch# show atm pnni aggregation node
PNNI nodal aggregation for local-node 2 (level=56, child PG level=60)
Complex node representation, exception threshold: 60%
Configured nodal aggregation modes (per service class):
CBR VBR-RT VBR-NRT ABR UBR
~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~
best-link best-link best-link best-link aggressive
Summary Complex Node Port List:
Port ID Rem Inn Agg-Token Border Cnt In-Spoke Out-Spoke Agg-Accur
~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~ ~~~~~~~~~~
21FB000 12 0 1 default default ok
2371000 13 0 1 default default ok
Summary Complex Node Bypass Pairs List (exception bypass pairs only)
/~~~~~~~~ LOWER PORT ID ~~~~~~~~\ /~~~~~~~~ HIGHER PORT ID ~~~~~~~\
Port ID Rem Inn Agg-Token Inacc Port ID Rem Inn Agg-Token Inacc Exceptns
~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~ ~~~~~~~~ ~~~~~~~ ~~~~~~~~~~ ~~~~~ ~~~~~~~~
21FB000 12 0 no 2371000 13 0 no fwd rev
The tasks in the following sections describe how to tune the PNNI protocol parameters:
PNNI uses the Hello protocol to determine the status of neighbor nodes and 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 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | node node_index | At the configure ATM router prompt, enter node configuration mode. The prompt changes to Switch(config-pnni-node)# |
| 3 | Configure Hello database synchronization and flooding parameters. | |
| 4 | Configure PTSE significant change percent number. |
The following example shows how to configure the PTSE refresh interval to 600 seconds:
Switch(config-pnni-node)# ptse refresh-interval 600
The following example shows how to configure the retransmission of the Hello timer to 60 seconds:
Switch(config-pnni-node)# timer hello-interval 60
To display the ATM PNNI Hello, database synchronization, and flooding configuration, use the following privileged EXEC command:
| Command | Task |
|---|---|
Display the ATM PNNI Hello, database synchronization, and flooding configuration. |
The following example shows the ATM PNNI Hello, database synchronization, and flooding configuration using the show atm pnni local-node privileged EXEC command:
Switch# show atm pnni local-node
PNNI node 1 is enabled and running
Node name: Switch
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
The resource management (RM) poll interval specifies how often PNNI polls RM to update the values of link metrics and attributes. You can configure the resource poll interval to control the tradeoff 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 RM poll interval, 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 Switch(config-atm-router)#. |
| 2 | resource-poll-interval seconds | Configure the resource management poll interval. |
The following example shows how to configure the RM poll interval to 10 seconds:
Switch(config)# atm router pnni Switch(config-atm-router)# resource-poll-interval 10
To display the RM poll interval configuration, use the following EXEC command:
| Command | Task |
|---|---|
Display the RM poll interval configuration. |
The following example shows the RM poll interval configuration using the show atm pnni resource-info EXEC command:
Switch# 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 ATM1/0/0 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 Interface ATM1/0/3 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>
You can collect the following statistics about the routing of ATM connections:
To enable statistics collection, perform these steps, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | At the configure prompt, enter ATM router PNNI mode from the terminal. The prompt changes to Switch(config-atm-router)# | |
| 2 | statistics [call] | Enable ATM PNNI statistics gathering. |
The following example shows how to enable PNNI ATM statistics gathering:
Switch(config)# atm router pnni Switch(config-atm-router)# statistics call
To display the ATM PNNI statistics, use the following privileged EXEC command:
| Command | Task |
|---|---|
show atm pnni statistics [call] | Display the ATM PNNI statistics. |
The following example shows the ATM PNNI statistics using the show atm pnni statistics privileged EXEC command:
Switch# 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
Posted: Fri Apr 9 13:11:16 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.