Cisco Systems IGX 8400 manual UXM-E in Trunk Mode, Routing over Cell Trunks Only, Cbr, Vbr, Abr

Universal Switching Module Enhanced

•8.3 and 9.3

•9.4 and the public network

Step 2 Configure trunk 8.1, 8.2, and 8.3 to use VPC 101, 102, and 103, respectively.

Step 3 Add 3 VPC connections from 9.1, 9.2, and 9.3 to 9.4. At the far end, use the same VPCs.

Routing over Cell Trunks Only

You can specify trunk cell routing only as an option when you add a connection between UXM-E, ASI, or BXM ports. When you enable trunk cell routing, switch software routes across only the cell-based trunk cards BNI, BXM, and UXM-E: no conversion to FastPackets occurs on the route. If you disable trunk cell routing, the routing process can select a FastPacket-based trunk and so decrement the number of available gateway connections. Also, using a FastPacket-based trunk may result in increased network delays. Therefore, enabling trunk cell routing is the preferred choice when you add a connection at a BNI, BXM, or UXM-E.

If you add connections at other port cards, such as a UFM or ALM/A, switch software does not display the trunk cell routing option.

On the CLI, the addcon prompt for this option appears as “trunk cell routing restrict y/n?” It appears after you enter either the ATM class of service or after you finish specifying all the individual bandwidth parameters that apply to the current connection type. You can specify whether the default for trunk cell routing is “Yes” or “No” through the cnfnodeparm (superuser) command.

The UXM-E in Trunk Mode

The UXM-E trunk can communicate ATM cells that originated at an ATM endpoint or—through its on-board gateway functionality—FastPacket-based traffic such as voice, data, and Frame Relay. A UXM-E trunk can connect to the following trunk cards:

•

•

UXM-E

BXM

Types of Supported Traffic

As previously stated, the UXM-E trunk can connect to only another UXM-E trunk or a BXM trunk. On the other hand, the types of traffic that traverse a UXM-E trunk can originate at ATM ports or other types of ports. The types of traffic that a cell on a UXM-E trunk can carry appear in Table 4-7. Table 4-7shows the traffic types that ATM cells can carry where the payload originated as a FastPacket.

Table 4-7 Traffic from FastPacket-Based Cards

Traffic Type

Timestamped

Non-timestamped

Voice

Bursty data A

Bursty data B

High priority

CBR, VBR, ABR

Trunk Cards 4-13