IBM Network Media Translation Commands

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
11.2 F	This command was introduced.

Usage Guidelines

This command allows QLLC to accept all inbound X.25 calls, provided that the QLLC Call User Data (CUD) is in the call packet and the destination X.121 address in the call packet matches the serial interface's configured destination X.121 address or subaddress. When using this command, the source X.121 address does not need to be configured via an x25 map qllc command for the call to be accepted.

This command is applicable to QLLC support for DLSw+, APPN, and DSPU. It is not applicable to QLLC support for SRB and RSRB.

Examples

The following example enables QLLC connectivity for DLSw+ and allows QLLC to accept all inbound X.25 calls. Every X.25 connection request for X.121 address 0308 with QLLC CUD is directed to DLSw+. The first SVC to be established will be mapped to virtual MAC address 4000.0B0B.0001. If a call comes in with an X.121 address of 0308, the call will be forwarded to MAC address 4001.1161.1234.

interface serial 0
 encapsulation x25
 x25 address 0308
 qllc accept-all-calls
 qllc dlsw vmac 4000.0B0B.0001 500 partner 4001.1161.1234

Related Commands

Command	Description
x25 map qllc	Specifies the X.121 address of the remote X.25 device with which communication is planned using QLLC conversion.

Syntax Description

virtual-mac-addr

MAC address associated with the remote X.25 device, as defined using the x25 map qllc or x25 pvc qllc interface configuration commands. This address is written as a dotted triple of four-digit hexadecimal numbers.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

The qllc npsi-poll command is necessary only when the upstream device is a FEP running NPSI and the downstream device is a PU 2.

This command is necessary because in a Token Ring or RSRB environment the LAN attached devices start up by sending a null exchange ID packet upstream. If the Cisco IOS software forwards this null XID to an X.25-attached FEP, the FEP responds as if it were connecting to an PU2.1 device, and breaks the connection when the PU 2 next sends an XID Format 0 Type 2. The qllc npsi-poll command intercepts any null XID packet that the software receives on the LAN interface, and returns a null XID response to the downstream device. It continues to allow XID Format 3 and XID Format 0 packets through the X.25 device.

Examples

The following example facilitates a connection between a FEP running NPSI and a downstream PU 2.0:

qllc npsi-poll 0100.0000.0001

Related Commands

Command	Description
qllc srb	Enables QLLC conversion on a serial interface configured for X.25 communication.
sdlc qllc-prtnr	Establishes correspondence between an SDLC and QLLC connection.
x25 map qllc	Specifies the X.121 address of the remote X.25 device with which communication is planned using QLLC conversion.
x25 pvc qllc	Associates a virtual MAC address with a PVC for communication using QLLC conversion.

Syntax Description

virtual-mac-addr	MAC address associated with the remote X.25 device, as defined using the x25 map qllc or x25 pvc qllc interface configuration commands. This address is written as a dotted triple of four-digit hexadecimal numbers.
mac-addr	48-bit MAC address of the Token Ring host that will communicate with the remote X.25 device.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

When the Cisco IOS software receives an incoming call from the designated X.121 address, it opens an LLC2 connection with the device at the given MAC address. Both the MAC address of the Token Ring device and the virtual MAC address for the remote X.25 device with which it is to communicate are required in order for the software to initiate connections with the Token Ring device. This allows the Token Ring host to be permanently ready to accept a connection rather than requiring operator action at the host to initiate the connection with the X.25 device.

You must issue the qllc partner command for each remote X.25 device that will communicate with the local Token Ring host through this interface.

Syntax Description

virtual-mac-addr	MAC address associated with the remote X.25 device, as defined using the x25 map qllc or x25 pvc qllc interface configuration commands. This address is written as a dotted triple of four-digit hexadecimal numbers.
ssap	Source SAP value. It can be a decimal number in the range 2 to 254. The default is 4.
dsap	Destination SAP value. It can be a decimal number in the range 2 to 254. The default is 4.

Defaults

The default source SAP value is 4.

The default destination SAP value is 4.

Command Modes

Interface configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

A SAP can be viewed as a port through which a higher-layer application can communicate with its counterpart (peer) operating on another system. While the standard SAP value for IBM devices is 4, other values are allowed.

Syntax Description

virtual-mac-addr	MAC address associated with the remote X.25 device, as defined using the x25 map qllc or x25 pvc qllc interface configuration commands. It can be 1 to 15 digits long.
srn	Source ring number. This value defines a virtual ring for all of the remote X.25 devices attached to the QLLC interface.
trn	Target ring number. It must be a virtual ring group that has been defined with the source-bridge sdllc-local-ack global configuration command.

Defaults

QLLC conversion is not enabled.

Command Modes

Interface configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

Any number of QLLC conversion connections using the same X.25 serial interface can share a common source ring. However, this source ring must be a unique hexadecimal ring number within the source-bridged network.

Syntax Description

virtual-mac-addr	MAC address associated with the remote X.25 device, as defined using the x25 map qllc or x25 pvc qllc interface configuration command. This address is written as a dotted triple of four-digit hexadecimal numbers.
xid	Combined XID IDBLK and XID IDNUM you are associating with the X.25 device at this X.121 address. This hexadecimal value must be four bytes (eight digits) in length.

Defaults

XID processing is not enabled.

Command Modes

Interface configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

Most QLLC installations do not need the qllc xid configuration command. It is only needed if the remote X.25 device is not configured to send its own XID. This is only possible for a device that is attached via a permanent virtual circuit (PVC). Even so, most devices that are connected via X.25 will send their own XIDs. Use the qllc xid command when the Token Ring host requires login validation for security purposes and the remote X.25 device does not send an XID. The XID value is used to reply to XID requests received on the Token Ring (LLC2) side of the connection. XID requests and responses are usually exchanged before sessions are started. The XID response to the XID request from the Token Ring host will contain the information you configure using the qllc xid command. The host will check the XID response it receives with the IDBLK and IDNUM parameters (configured in VTAM). If they match, the Token Ring host will initiate a session with the router. If they do not match, the host will not initiate a session with the router.

Syntax Description

mac-address	MAC address of the Token Ring host.
sdlc-address	SDLC address of the serial device that will communicate with the Token Ring host.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Both the MAC address of the Token Ring host and the SDLC serial line address are required to initiate connections with the Token Ring host.

The Token Ring host and the serial device communicate with each other through the Cisco IOS software. Although the device is said to initiate connections, the software actually initiates connections with the Token Ring host on behalf of the serial device. As part of Cisco's SDLLC implementation, the serial device "thinks" that it is communicating with a host also on a serial line. It is actually the software that does all the frame and protocol conversions between serial and Token Ring devices.

There are two conditions under which the Cisco IOS software will attempt to initiate a connection to a host on behalf of a serial device:

• When the serial device attached to the router is powered on. In this case, the router attached to the serial line detects a change in interface signals and initiates a connection with the Token Ring hosts by exchanging explorer and XID packets.

• When a previously shut down serial interface is brought back on-line. When the no shutdown command is issued, the software will detect a change in the serial line state from down to up and initiate a session with the Token Ring host by exchanging explorer and XID packets.

The Cisco IOS software will continue trying once a minute to initiate a connection whenever one of these two conditions is met, until the host responds to its requests. When you no longer want the software to initiate connections with a host, use the no sdllc partner command.

Note   For device-initiated sessions, the host will check the IDBLK and IDNUM parameters of the serial device it receives in the XID packet against the information configured on the host. If the information in the XID packet does not match with what is configured on the host, the host will drop the session. Therefore, for device-initiated connections, always specify the correct IDBLK and IDNUM parameters on the router serial interfaces with the sdllc xid command.

Examples

In the following example, a serial device at SDLC address C2 wants to initiate a connection with a Token Ring host at MAC address 4000.0122.0001. The router initiates the connection on behalf of a serial device:

! sample global command 
source-bridge ring-group 100
!
interface serial 0 
! router initiates connections with Token Ring host at MAC address 
! 4000.0122.0001 on behalf of serial device c2
sdllc partner 4000.0122.0001 c2

Related Commands

Command	Description
sdllc xid	Specifies an XID value appropriate for the designated SDLC station associated with this serial interface.

Syntax Description

value

Frame size in bytes. Possible values include 516, 1500, 2052, 4472, 8144, 11407, and 17800. The default is 516 bytes.

Defaults

516 bytes

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Faster screen updates to 3278-style terminals often can be obtained by allowing the Token Ring FEP to send as large a frame as possible and by allowing the Cisco IOS software to segment the frame into multiple SDLC I-frames.

Examples

In the following example, the software can send or receive a frame as large as 11407 bytes from the LLC2 primary station. Any frames larger will be fragmented by the software.

! sample global command 
source-bridge ring-group 100
!
interface serial 3 
! largest frame sent or received on serial 3 is 11407 bytes
sdllc ring-largest-frame 11407

Related Commands

Command	Description
source-bridge remote-peer interface	Specifies a point-to-point direct encapsulation connection.
source-bridge remote-peer tcp	Identifies the IP address of a peer in the ring group with which to exchange source-bridge traffic using TCP.

Syntax Description

sdlc-address	MAC address associated with the remote SDLC device.
ssap	Source SAP value. It must be in the range 1 to 254. The default is 4.
dsap	Destination SAP value. It must be in the range 1 to 254. The default is 4.

Defaults

The default source and destination SAP values for IBM SNA devices is 4.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Syntax Description

address	Address of the SDLC station that will communicate with the Token Ring host.
value	Largest frame size that can be sent or received by this SDLC station. The default is 265 bytes.

Defaults

265 bytes

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Most SDLC devices are limited to frames of 265 bytes. I-frames received from the Token Ring station that are larger than this size will be properly fragmented.

Examples

In the following example, the Cisco IOS software can send or receive a frame as large as 265 bytes (the default) from the SDLC station at address C6. Any frames larger will be fragmented by the software.

! sample global command 
source-bridge ring-group 100
!
interface serial 4 
! largest frame sent or received on serial 4 is 265 bytes
 sdllc sdlc-largest-frame c6 265

Syntax Description

xxxx.xxxx.xx00	MAC address to be assigned to the serial interface.
lr	SDLLC virtual ring number.
bn	SDLLC bridge number.
tr	SDLLC target ring number.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Every control unit hooked off the serial line requires a virtual Token Ring address (VTRA). This usually is assigned by the system administrator as a locally administered MAC address (unique across the network).

When you enable SDLLC Media Translation by specifying the sdllc traddr command on a serial interface, you must specify a VTRA for each serial station attached to the serial line. The last two hexadecimal digits (that is, the last byte) of the VTRA must be 00. The Cisco IOS software uses this byte to represent the SDLC address of a station on the serial link.

Note   Addresses in the range xxxx.xxxx.xx00 to xxxx.xxxx.xxFF are reserved for use by the Cisco IOS software. You must adhere to this addressing requirement. If you do not follow this addressing requirement, there may be a conflict between the VTRA and the addresses reserved by the software for the SDLC link.

The variables lr, bn, and tr represent the SDLLC virtual ring number, bridge number, and target ring number, respectively, that you assign to the interface. In design, the serial interface appears to be a ring, lr, on a source-route bridged network, and ties in through the bridge, bn, to the virtual ring-group, tr. This provides access to other, real rings through remote source-route bridging source-bridge remote-peer commands. Note that SDLLC can be configured on a router containing no Token Ring interface cards.

The sdllc traddr command automatically turns on the LLC2 process with default values. To change any of the LLC2 parameters, specify their values on the serial interface that is being enabled for SDLLC. This is done on the serial interface, even though LLC2 does not technically run on the serial interface, but on the SDLLC virtual ring associated with the serial interface. LLC2 commands can be configured after specifying the sdllc traddr command.

Examples

In the following example, SDLLC media translation is enabled off the serial 0 interface to a serial station at MAC address 0110.2222.3300. The SDLLC virtual ring number is 8, the bridge number is 1, and the target ring number is 100.

! global command to apply commands to the ring group 
source-bridge ring-group 100
! remote peer at IP address 131.108.1.1 belongs to ring group 100 and uses
! tcp as the transport 
source-bridge remote-peer 100 tcp 131.108.1.1
source-bridge remote-peer 100 tcp 131.108.2.2
!
interface serial 0
 encapsulation sdlc-primary
! establish address of SDLC station off serial-0 as c1
 sdlc address c1
! enable SDLLC media translation to serial station 0110.2222.3300 
! on virtual ring 8, bridge 1, to target ring 100
 sdllc traddr 0110.2222.3300 8 1 100

Related Commands

Command	Description
sdllc sap	Associates a SAP value other than the default SAP value with a serial interface configured for SDLLC.
source-bridge remote-peer interface	Specifies a point-to-point direct encapsulation connection.
source-bridge remote-peer tcp	Identifies the IP address of a peer in the ring group with which to exchange source-bridge traffic using TCP.

Syntax Description

address	Address of the SDLC station associated with this interface.
xxxxxxxx	XID the Cisco IOS software will use to respond to XID requests received on the Token Ring (LLC2) side of the connection. This value must be 4 bytes (8 digits) in length and is specified with hexadecimal digits.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

XID requests and responses are usually exchanged before sessions are started. Be sure that the XID value configured on the router matches the IDBLK and IDNUM parameters configured on the host. The XID response to an XID request from the Token Ring host will contain the information you configured in the sdllc xid command. The host will check the XID response it receives with the IDBLK and IDNUM parameters (that are configured in virtual telecommunications access method (VTAM)). If they match, the Token Ring host will initiate a session with the router. If they do not match, the host will not initiate a session.

Examples

The following example specifies an XID value of 01720002 at address C2:

! sample global command 
source-bridge ring-group 100
!
interface serial 0
! sdllc exchange identification value of 01720002 at address c2
 sdllc xid c2 01720002

Related Commands

Command	Description
sdllc partner	Enables device-initiated connections for SDLLC.Must be specified for the serial interface that links to the serial line device.

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
10.3	This command was introduced.

Examples

The following is sample output from the show qllc command.

Router# show qllc
 
QLLC Connections:
Serial2: 1000.5a35.3a4f->1000.5a59.04f9. SAPs 4 4. Rings Src 200, Tgt 100.
State Connect
Remote DTE 1002. QLLC Protocol State NORMAL lci 1 (PVC)
 

In the display, the first two lines of the show qllc command show that there is a QLLC session between a Token Ring device and an X.25 remote device. The X.25 device has a virtual MAC address of 100.5a35.3a4f with a SAP of 04. It is using a PVC with logical channel number 1. The Token Ring device has a MAC address of 1000.5a59.04f9 with a SAP of 04. The state of the QLLC session is CONNECTED.

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
10.0	This command was introduced.

Examples

The following is sample output from the show sdllc local-ack command:

Router# show sdllc local-ack
 
local 1000.5a59.04f9, lsap 04, remote 4000.2222.4444, dsap 04
llc2 = 1798136, local act state = connected
Passthrough Rings: 4 7
 

In the display, the first two lines of the show sdllc local-ack command show that there is a local acknowledgment session between two Token Ring devices. The device on the local ring has a MAC address of 1000.5a59.04f9 with a SAP of 04. The remote device has a MAC address of 4000.2222.4444 with a SAP of 04. The state of the local acknowledgment session is connected.

The passthrough rings display is independent of the rest of the show sdllc local-ack command. The passthrough rings display indicates that there are two rings, 4 and 7, configured for passthrough. This means that stations on these rings will not have their sessions locally acknowledged but will instead have their acknowledgments end-to-end.

Syntax Description

This command has no arguments or keywords.

Defaults

QLLC local acknowledgment is disabled.

Command Modes

Global configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

In a remote source-route bridged topology, QLLC local acknowledgment is used to configure the QLLC conversion router (connecting the remote X.25 devices) to exchange local acknowledgment information with the Token Ring router (on the Token Ring side of the cloud). This Token Ring device has been configured for LLC2 local acknowledgment using the source-bridge remote peer tcp local-ack command.

You only have to issue the source-bridge qllc-local-ack command on the QLLC conversion router. When this command is issued, all of the QLLC conversion sessions are locally acknowledged at the Token Ring interface of the Token Ring router with which it is communicating using QLLC conversion.

Examples

The following configuration indicates that the local router (131.108.2.2) QLLC conversion sessions will be locally acknowledged at the remote router:

source-bridge ring-group 100
source-bridge remote-peer 100 tcp 131.108.1.1 local-ack
source-bridge remote-peer 100 tcp 131.108.2.2
source-bridge qllc-local-ack

Related Commands

Command	Description
source-bridge remote-peer tcp	Identifies the IP address of a peer in the ring group with which to exchange source-bridge traffic using TCP.
source-bridge sdllc-local-ack	Activates local acknowledgment for SDLLC sessions on a particular interface.

Syntax Description

ring-group	Ring group number. This ring group number must match the number you have specified with the source-bridge ring-group command. The valid range is 1 to 4095.
interface-name	Name of the serial interface over which to send source-route bridged traffic.
mac-address	(Optional) MAC address for the interface you specify using the interface-name argument. This argument is required for nonserial interfaces. You can obtain the value of this MAC address by using the show interfaces command, and then scanning the display for the interface specified by interface-name.
lf size	(Optional) Maximum size frame to be sent to this remote peer. The Cisco IOS software negotiates all transit routes down to this size or lower. This argument is useful in preventing timeouts in end hosts by reducing the amount of data they have to transmit in a fixed interval. The legal values for this argument are 516, 1500, 2052, 4472, 8144, 11407, and 17800 bytes.

Defaults

No point-to-point direct encapsulation connection is specified.

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Use this command to identify the interface over which to send source-route bridged traffic to another router/bridge in the ring group. A serial interface does not require that you include a MAC-level address; all other types of interfaces do require MAC addresses.

Note   The two peers using the serial-transport method will only function correctly if there are routers at the end of the serial line that have been configured to use the serial transport. The peers must also belong to the same ring group.

Examples

The following example shows how to send source-route bridged traffic over serial interface 0 and Ethernet interface 0:

! send source-route bridged traffic over serial 0 
source-bridge remote-peer 5 interface serial 0 
! specify MAC address for source-route bridged traffic on Ethernet 0
source-bridge remote-peer 5 interface ethernet 0 0000.0c00.1234 

Related Commands

Command	Description
show interfaces	Displays statistics for all interfaces configured on the router or access server.
source-bridge remote-peer tcp	Identifies the IP address of a peer in the ring group with which to exchange source-bridge traffic using TCP.

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command must be issued only on a router with a serial interface. Once the command is issued, all SDLLC sessions between the two devices will be locally acknowledged. You cannot selectively choose which SDLLC sessions are to be locally acknowledged and which are not. Also, local acknowledgment is not supported when the LLC2 station is attached to Ethernet rather than to Token Ring.

Note   You must use the TCP encapsulation option if you use local acknowledgment for SDLLC.

Examples

The following example activates local acknowledgment for SDLLC sessions:

source-bridge ring-group 100
source-bridge remote-peer 100 tcp 131.108.1.1 local-ack
source-bridge remote-peer 100 tcp 131.108.2.2
source-bridge sdllc-local-ack

Syntax Description

virtual-mac-addr	Virtual MAC address.
x121-addr	X.121 address of the remote X.25 device you are associating with this virtual MAC address. It can be from 1 to 15 digits long.
x25-map-options	(Optional) Additional functionality that can be specified for originated calls. Can be any of the options listed in Table 40.

Defaults

No association is made.

Command Modes

Interface configuration

Command History

Release	Modification
10.3	This command was introduced.

Usage Guidelines

The central notion that binds the QLLC conversion interface to the X.25 and SRB facilities is the X.25 address map. For each remote client an X.121 address is associated with a virtual MAC address. The rest of the configuration is specified by using the virtual Token Ring address to refer to the connection.

When a Token Ring device wishes to open communications with another device, it will send the request to the address it knows, which is the MAC address. The Cisco IOS software accepts this connection request and must transform it into a known X.121 address. The x25 map qllc command matches the MAC address with the X.121 address.

You must enter a mapping for each X.25 device with which the router will exchange traffic.

All QLLC conversion commands use the virtual-mac-addr parameter that you define with the x25 map qllc command to refer to the connection.

You use the x25 map qllc command in conjunction with the qllc srb command.

Examples

In the following example, the x25 map qllc command is used to associate the remote X.25 device at X.121 address 31104150101 with the virtual MAC address 0100.000.0001:

interface serial 0
 encapsulation x25
 x25 address 31102120100
 x25 map qllc 0100.0000.0001 31104150101
 qllc srb 0100.0000.0001 201 100

Related Commands

Command	Description
qllc accept-all-calls	Enables the router to accept a call from any remote X.25 device.
qllc srb	Enables QLLC conversion on a serial interface configured for X.25 communication.

Syntax Description

circuit	PVC you are associating with the virtual MAC address. This must be lower than any number assigned to switched virtual circuits.
x121-address	X.121 address.
x25-map-options	(Optional) Additional functionality that can be specified for originated calls. Can be any of the options listed in Table 40 shown earlier in this publication.

Defaults

No association is made.

Command Modes

Interface configuration

Command History

Release	Modification
11.0	This command was introduced.

Usage Guidelines