Cisco Cisco Expressway

Appendix 3: Connecting Expressway to a cluster
of Unified CM nodes

When connecting Expressway to a cluster of Unified CM nodes, Expressway needs to be able to route calls
to each Unified CM node.

This can be done in 2 ways, in order of preference:

1. With a single neighbor zone in Expressway with the Unified CM nodes listed as location peer addresses.

2. By using DNS SRV records and an Expressway DNS zone.

Note that both options ensure that the Expressway to Unified CM call load is shared across Unified CM
nodes.

Option 1: Using a single neighbor zone

Unified CM configuration

When in a cluster, Unified CM needs to accept calls routed to number@domain (instead of number@<ip
address of Unified CM>) so that Expressway can send the call to any Unified CM node without having to
make sure that the domain portion matches the IP address of the node that the call is being sent to.

Ensure that the Cluster Fully Qualified Domain Name (

System > Enterprise parameters

, in the

Clusterwide Domain Configuration

section) is set to the same domain as the video network, for example

exp.domain.

Expressway-C configuration

The Expressway configuration requires an update to the neighbor zone:

1. Go to

Configuration > Zones

2. Select the Unified CM neighbor zone.

3. Configure the fields as follows:

Peer 1 address

IP address of Unified CM node 1, or the domain of Unified CM node 1.

Peer 2 address

IP address or the domain of Unified CM node 2.

Peer 3 address

IP address or the domain of Unified CM node 3, or blank if no Unified CM node 3.

.... up to Peer 6
address

... repeat up to the IP address or the domain of Unified CM node 6, or leaving it blank if
there is no Unified CM node.

Option 2: Using a DNS zone