Cisco Cisco TelePresence Video Communication Server Expressway
Appendix 6 – Connecting Cisco VCS to a cluster of CUCM nodes
Cisco VCS Deployment Guide: CUCM v6.1, 7 and 8 with Cisco VCS X6 using a SIP trunk
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Appendix 6 – Connecting Cisco VCS to a
cluster of CUCM nodes
cluster of CUCM nodes
When connecting Cisco VCS to a cluster of CUCM nodes, Cisco VCS needs to be able to route calls
to each of these CUCM nodes. This can either be done by setting up multiple zones – one per CUCM
node, then setting up a set of prioritized search rules to route calls to each of the zones in the
preferred order (priority values different for each search rule). An alternative method is to use DNS
SRV records and a Cisco VCS DNS zone. This is a better approach because call load can be shared
across CUCM nodes.
to each of these CUCM nodes. This can either be done by setting up multiple zones – one per CUCM
node, then setting up a set of prioritized search rules to route calls to each of the zones in the
preferred order (priority values different for each search rule). An alternative method is to use DNS
SRV records and a Cisco VCS DNS zone. This is a better approach because call load can be shared
across CUCM nodes.
Configuration for Cisco VCS to use a DNS Zone to contact a
cluster of CUCM nodes
cluster of CUCM nodes
CUCM configuration
When in a cluster, CUCM needs to accept calls routed to number@domain (instead of
number@<ip address of CUCM>) so that Cisco VCS can send the call to any CUCM node without
having to make sure that the domain portion matches the IP address of the node that the call is being
sent to.
number@<ip address of CUCM>) so that Cisco VCS can send the call to any CUCM node without
having to make sure that the domain portion matches the IP address of the node that the call is being
sent to.
1. Go to System > Enterprise parameters, and find the Clusterwide Domain Configuration section.
2. Set the Organization Top Level Domain to the same domain as the video network, vcs.domain
for example.
DNS Server configuration
Configure the DNS server that Cisco VCS has been configured to use with DNS SRV records for the
CUCM cluster.
CUCM cluster.
_sips._tcp.fqdn_of_cucm_cluster
for TLS connectivity (one record for each CUCM node)
or
_sip.tcp.fqdn_of_cucm_cluster
for TCP connectivity (one record for each CUCM node)
Cisco VCS Control configuration
Cisco VCS configuration requires 3 steps:
Create a CUCM DNS zone
Adjust search rule
Delete the old CUCM neighbor zone
Create a CUCM DNS zone
1. Go to VCS configuration > Zones.
2. Click New.
3. Configure the fields as follows:
Name
CUCM Cluster Neighbor DNS Zone
Type
DNS
Hop count
15