Table of Contents

Configuring Trunks

Setting Up a Trunk
Reconfiguring a Trunk
Removing a Trunk
Displaying or Printing Trunk Configurations

Adding an Interface Shelf

Configuring Trunks and Adding Interface Shelves

After you have configured the nodes, you must activate the trunks. Trunks are intranode communication links in a network. A trunk can connect any combination of IGX or BPX nodes.

This chapter describes:

• Configuring Trunks

• Adding an Interface Shelf

Before proceeding to this chapter, you should first complete the procedures in:

• Part 2, Installation

• Chapter 17, Initial BPX 8600 Node Configuration

For details on virtual trunking, see:

• Chapter 23, Configuring BXM Virtual Switch Interfaces

• Chapter 25, Configuring BXM Virtual Trunks

Configuring Trunks

Trunk characteristics are:

Table 18-1 shows the communication technology for each node type, card combination, and line type.

Setting Up a Trunk

Before executing the commands in this section, you must have finished setting up the nodes (see the "Initial BPX 8600 Node Configuration" chapter.) Also, the front and back cards that support the proposed line type and communication technology must reside in the slot intended for the trunk.

You can configure port, routing trunk, and feeder trunk interfaces simultaneously on a slot containing a BXM card. For example, you can up port 1 on a BXM slot as a trunk interface while also upping port 2 as a line interface. For BXM cards, you do not need to upgrade the firmware.

You cannot use a virtual trunk as an interface shelf (feeder) trunk; similarly, you cannot configure an interface shelf trunk to act as a virtual trunk. Similarly, you cannot terminate interface shelf (feeder) connections on a virtual trunk.

To set up a trunk:

Use the uptrk command to activate the port so that it can start to generate framing. It also determines whether the trunk is a physical-only trunk or a virtual trunk. The third digit you specify in the uptrk command (represented by slot.port.vtrk) indicates that the trunk is virtual. For details on virtual trunking, see Chapter 25, Configuring BXM Virtual Trunks.

Use uptrk at each end of the trunk. When the trunk is upped at only one end, the node detects the trunk as being in an alarm state (see dsptrks). Upping the trunk at both ends clears the alarm.

Step 2   Use the cnftrk command to override the trunk's default values. You must use cnftrk for virtual trunks, but it is an optional command for physical trunks. For virtual trunks, you must change the VPI to a non-0 value before executing addtrk.

If you use cnftrk, you must make the same changes at both ends of the trunk. To display existing trunk parameters, use the dsptrkcnf command. The configurable parameters are listed for each card type in Table 18-1. (The possible parameters are PKT for FastPackets, ATM cells, BNI if the trunk is a BNI card, or All.) Not all of these parameters apply to the BPX node.

After you configure the trunk and add the trunk (addtrk), you can respecify certain parameters. For example, a period of trunk use may give you enough information to indicate that you should change parameters to optimize how the trunk is used.

Step 3   Use addtrk to add the trunk. Adding the trunk makes the trunk a usable resource, so you can add connections (addcon) to carry traffic. You need only add one end of the trunk.

Reconfiguring a Trunk

This section describes how to change trunk parameters after you have added the trunk.

After you have added a trunk, you can reconfigure some parameters without first deleting the trunk (with deltrk). This means that you can reconfigure the following list of trunk and line parameters when the port is in use (active). The cnftrk display highlights all configurable parameters, and dims parameters that are not configurable.

The parameters that you can change without first deleting the trunk are:

• Restrict Control Card traffic ("PCC restrict")

• Pass sync

• Loop clock

• Statistical reserve

• Bursty data peak speed

• Bursty data peak average frame

• Idle Code (reconfigurable for trunk and line)

• User traffic

• Maximum PVC Channels

• Trunk Partitions SVC/PVC

• DS0 Map (IGX only, as of Release 9.2)

• Cable type/length

• Virtual trunk type

• Link type

• HCS Masking

• Payload Scrambling

• Frame Scrambling

• Gateway Channels

• Retained Links

• IMA link auto disabled

• IMA window size

• IMA max transition counts

• IMA link reenable time

• Traffic classes

• Recv Impedance

• Gateway Efficiency

• Cost of Trunk

• Deroute Delay Time

• Line T1 signalling (Line reconfiguration allowed)

• Line caching (Line reconfiguration allowed)

• Line CAS Switching (Line)

• Line Cnf slot.line (Line)

• Line Cnfg (Line)

• Line pct fast modem (Line)

• Trunk Receive Rate—On IGX, configurable after a trunk has been added.

• Trunk Transmit Rate—On BPX platforms, configurable after a trunk has been added.

Before making changes to any other trunk parameters, you must first delete the trunk (deltrk).

To display the current trunk parameters, use dsptrkcnf. If you can make all the needed parameter changes without deleting the trunk, execute cnftrk. Use cnftrk at both ends of the trunk.

To change parameters that require you to first delete the trunk:

Step 2   Execute cnftrk at both ends of the trunk to reconfigure parameters.

Step 3   Execute addtrk at only one end of the trunk to add the trunk.

Switch software triggers a reroute of connections only if a change to a parameter results in too few resources to support the current load of connections.

If you attempt to change one of these parameters, the other endpoint will be updated by switch software. It is not necessary to chagne both endpoints' parameters.

Before Release 9.2, changes made to the following three parameters caused a reroute on the trunk:

• Statistical reserve

• Trunk Partitions SVC/PVC

• Maximum PVC Channels

For example, any increase to Statistical reserve would cause a reroute of all connections on the trunk. Any changes you make to these parameters will cause reroutes to PVCs on the trunk only if resources are no longer available to support the current connection load

Note that MPLS partitions will not be affected by trunk/line reconfiguration, because label switching partitions cannot be inreased beyond the available number of resources.

For a trunk between a node running Release 9.2 and node running an earlier release (such as 9.1 or 8.5), you will be prompted that you can change a parameter only if both ends allow such a change.

Removing a Trunk

To remove a trunk:

Step 2   Use the dntrk command to down the trunk. Execute dntrk at both ends of the trunk.

Displaying or Printing Trunk Configurations

You can display the network trunk configuration on the screen or print it on the printer in a one-step process by using any one of the following commands.

• dsptrks
  Displays the current trunk configuration and alarm status at a node.

• prttrks
  Prints the current trunk configuration and alarm status at a node.

• dspnw
  Displays all trunks for each node in a domain.

• prtnw
  Prints all trunks for each node in a domain.

Adding an Interface Shelf

An interface shelf is a non-routing device that drives ATM cells to and from a BPX or IGX routing hub in a tiered network. (An interface shelf is also sometimes referred to as a feeder shelf.) An interface shelf can be:

• an IGX node configured as an interface shelf

• an MGX 8850 node configured as an interface shelf

• an MGX 8220 interface shelf

• an MGX 8800 interface shelf

• a Service Expanions Shelf (SES) with PNNI

For instructions on installing a Service Expansion Shelf in a BPX 8620 rack and initially powering up, see Cisco Service Expansion Shelf (SES) Hardware Installation Guide. To configure an SES PNNI for a BPX 8620, see the Cisco SES PNNI Controller Software Configuration Guide.

Because tiered network capability is a purchased option, personnel in the Technical Assistance Center (TAC) must first configure a node to serve as an interface shelf. Then you must use the cnftrk command to configure an interface shelf to use STI cell headers and BPX Addressing Mode (BAM).

Before you can add an MGX 8220 shelf to a tiered network, the shelf must be an available resource in the network. (For instructions on how to bring up an MGX 8220 shelf, see the MGX 8220 documentation.)

To add an interface shelf, use addshelf. See Figure3-7 for an illustration of the command sequence for setting up an interface shelf. (Note that addshelf and addtrk are mutually exclusive commands.)

To delete a feeder shelf, use delshelf.

To view conditions on a feeder trunk, use dspnode.

Table 18-3 show designations for various devices that can be used as interface shelves. To display these designations, use the display commands dspnw and dspnode. The dspnode command identifies the hub and feeder nodes and shows the alarm status.

Posted: Fri Jul 27 16:14:38 PDT 2001
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