Load Balancing Cluster Expressway C and E to MRA

[ANGEL FERNANDEZ SARABIA]

Hi, We have configurated 2 cluster of Expressway C and E to use the funcionality MRA with Cisco Jabber and Video/Call with B2B. All are working ok, but we do not undertand how it working about load balancing.

In incoming call to video equipment registers in CUCM, the load balancing is making with DNS external, but when the video equipoment make a external call to internet, allways is using the first Expressway C and first Expresway E ( there is not load balancing between cluster member).

Is necesary configure something to use this funcionality?

For the other wise, the cisco jabber register external, always use the traversal zone between Expressway-C and E but allways first equipment configured.

We do not understand the load balancing.

The versión of Expressway is 8.7

Best Regast.

[Patrick Sparkman]

When an outbound call gets placed from CUCM, a destination address gets chosen randomly, and no preference is given to one destination address over another.

When a call is received on your Expressway-C/E and is passed via the relevant zone to the remote cluster, it will be routed to whichever peer has the lowest resource usage. 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.

For external calls into your Expressway-E, that is determined how you have DNS configured, most common is SRV Records or Round Robin DNS.