Cisco Cisco Expressway
Neighboring between Expressway clusters
You can neighbor your local Expressway (or Expressway cluster) to a remote Expressway cluster; this
remote cluster could be a neighbor, traversal client, or traversal server to your local Expressway. In this
case, when a call is received on your local Expressway and is passed via the relevant zone to the remote
cluster, it will be routed to whichever peer in that neighboring cluster has the lowest resource usage. That
peer will then forward the call as appropriate to one of its external zones.
remote cluster could be a neighbor, traversal client, or traversal server to your local Expressway. In this
case, when a call is received on your local Expressway and is passed via the relevant zone to the remote
cluster, it will be routed to whichever peer in that neighboring cluster has the lowest resource usage. That
peer will then forward the call as appropriate to one of its external zones.
Lowest resource usage is determined by comparing the number of available media sessions (maximum -
current use) on the peers, and choosing the peer with the highest number. Peers that are in maintenance
mode are not considered.
current use) on the peers, and choosing the peer with the highest number. Peers that are in maintenance
mode are not considered.
When configuring a connection to a remote cluster, you create a single zone and configure it with details of all
the peers in the cluster. Adding this information to the zone ensures that the call is passed to that cluster
regardless of the status of the individual peers.
the peers in the cluster. Adding this information to the zone ensures that the call is passed to that cluster
regardless of the status of the individual peers.
You also need to enter the IP address of all peers in the remote cluster when the connection is via a
neighbor or traversal client zone. You do not do this for traversal server zones, as these connections are
not configured by specifying the remote system's IP address.
neighbor or traversal client zone. You do not do this for traversal server zones, as these connections are
not configured by specifying the remote system's IP address.
Note: Systems that are configured as peers must not also be configured as neighbors to each other, and vice
versa.
versa.
Neighboring your clusters
To neighbor your local Expressway (or Expressway cluster) to a remote Expressway cluster, you create a
single zone to represent the cluster and configure it with the details of all the peers in that cluster:
single zone to represent the cluster and configure it with the details of all the peers in that cluster:
1. On your local Expressway (or, if the local Expressway is a cluster, on the master peer), create a zone of
the appropriate type. This zone will represent the connection to the cluster.
2. In the Location section, enter the IP address or FQDN of each peer in the remote cluster in the Peer 1 to
Peer 6 address fields.
Note that:
n
Ideally you should use IP addresses in these fields. If you use FQDNs instead, each FQDN must be
different and must resolve to a single IP address for each peer.
different and must resolve to a single IP address for each peer.
n
The order in which the peers in the remote Expressway cluster are listed here does not matter.
n
Whenever you add an extra Expressway to a cluster (to increase capacity or improve redundancy, for
example) you will need to modify any Expressways which neighbor to that cluster to let them know about
the new cluster peer.
example) you will need to modify any Expressways which neighbor to that cluster to let them know about
the new cluster peer.
Cisco Expressway Cluster Creation and Maintenance Deployment Guide (X8.5.2)
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Neighboring between Expressway clusters