Installation guide

Trunk Cards 4-15

Universal Switching Module Enhanced

IMA characteristics are as follows:

• All physical ports of an IMA trunk use the same line conﬁguration.

• The node maintains a set of retained links for the IMA trunk to keep it active. The IMA trunk

does not fail unless the number of active trunks is less than the user-speciﬁed number of retained

links.

• The IMA trunk can provide a clock source or clock path (see cnftrk command). The ﬁrst (the

lowest numbered) available physical line is used. If this line fails, the next available line within

the IMA provides the clock source or clock path.

• Full support for individual physical line alarms and statistics.

To specify the range of ports for an IMA trunk, you can use either Cisco WAN Manager or the

command-line interface (CLI). To deﬁne an IMA trunk on the CLI, use the uptrk command:

uptrk slot.start_port-end_port

For example, you could enter uptrk 8.1–4. Subsequently, you would refer to this logical trunk by

using only the slot number and ﬁrst port number—8.1 in this example—when you use other

commands, such as addtrk, deltrk, cnftrk, and so on. Commands for viewing IMA information

also include dspportstats, dspphyslns, dsptrkcnf, dspfdr, dspnode, and dspphyslnstathist.

Adding an IGX Feeder

The IMA feeder node feature provides redundancy in case one of the physical lines on an IMA trunk

fails. This reduces the chance of a single point of failure when a single feeder trunk is out of service.

In addition, this feature allows you to conﬁgure the services on a feeder node instead of a routing

node.

Figure 4-5 shows an example of an IGX feeder topology.

Figure 4-5 Sample IGX Feeder Topology

Currently supported on the IGX, a Service Expansion Shelf (SES) can function as a feeder node

connected to an IGX routing node using a UXM-E OC-3 interface. The UXM-E feeder node feature

adds the capability to support the UXM-E interface and the IGX as a feeder node. The routing node

can be an IGX or a BPX/BXM-T3, BPX/BXM-E3, or BNI. The UXM-E interface type T1/E1,

nxT1/E1, T3/E3, and OC-3, SMF/MMF Extra Long Reach can be used to connect an IGX feeder

node to the IGX/BPX routing node.

Note For a summary of commands you use to bring up an IGX node, refer to the section “IGX

Conﬁguration Summary” in Cisco IGX 8400 Series Installation and Conﬁguration.

IGX-hub IGX-hubIGX-feeder

IMA-trunk 8.3-8

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IMA cloud