Designing Dial Plan with Separate Cisco CUCM Cluster and single CMS Cluster

In this scenario, there are two separate CUCM clusters.

  • The first cluster is located in HQ-site with HQ-CUCM and HQ-CUP.
  • The second cluster is located in BB-site with BB-CUCM and BB-CUP.

A Cluster of two Cisco Meeting Servers are distributed accross sites. HQ-CMS is deployed in HQ-Site while BB-CMS is deployed in BB-Site.

Both CMS are clustered and share the same space with the User Part URI 882222.

To optimise intersite bandwidth usage, the local CUCM should send calls to join meeting from local users to local Cisco Meeting Server, if the local CMS is not available, the remote Cisco CMS can be used as a backup.

To optimize load balancing with failover, if the local CMS is not available, a prefix « 8 » must be added when a user dials 882222 by the local CUCM and the called number 8-882222 will be presented to the remote CUCM.

The remote CUCM must have a route pattern 8.88XXXX to route the call to remote CMS. The prefix « «8 » must be stripped before sending the call so that the call number 882222 will match the User Part URI of the space World Cup Espana 1982.

SIP Trunks are configured as follow :

  • HQ-CUCM and BB-CUCM are configured with a SIP Trunk.
  • HQ-CUCM is configured with SIP Trunk to HQ-CMS.
  • BB-CUCM is configured with SIP Trunk to BB-CMS.

To design our dial plan.

On each CUCM, we need two Route Groups.

On HQ-CUCM.

  • The Route Group named RG-HQ-CMS-LOCAL contains SIP Trunk to HQ-CMS.
  • The Route Group named RG-BB-CMS-REMOTE contains SIP Trunk to BB-CUCM.

On BB-CUCM.

  • The Route Group named RG-BB-CMS-LOCAL contains SIP Trunk to BB-CMS.
  • The Route Group named RG-HQ-CMS-REMOTE contains SIP Trunk to HQ-CUCM.

Now we need two Route Lists on each CUCM.

On HQ-CUCM.

  • The first Route List is named RL-HQ-CMS-Failover, it contains the Route Groups RG-HQ-CMS-LOCAL placed first in the list and RG-BB-CMS-RMOTE.
  • The second Route List is named RL-HQ-CMS and it contains the Route Group RG-HQ-CMS-LOCAL.

On BB-CUCM.

  • The first Route List is named RL-BB-CMS-Failover, it contains the Route Groups RG-BB-CMS-LOCAL placed first in the list and RG-HQ-CMS-RMOTE.
  • The second Route List is named RL-BB-CMS and it contains the Route Group RG-BB-CMS-LOCAL.

Finally, we configure two Route Patterns on each CUCM.

On HQ-CUCM.

  • Route Pattern 882XXX that points to to the Route List RL-HQ-CMS-Failover.
  • Route Pattern 8.882XXX that points to to the Route List RL-HQ-CMS.

On BB-CUCM.

  • Route Pattern 882XXX that points to to the Route List RL-BB-CMS-Failover.
  • Route Pattern 8.882XXX that points to to the Route List RL-BB-CMS.

To connect successfully jabber client to the remote CMS in the event that the local CMS is not available we need to perform two digits manipulation of the dialed number 882222.

The first digits manipulation is to add prefix « 8 » to the called number 882222 when the call from Zico user located at the HQ-Site is sent to the remote CMS BB-CMS through the SIP Trunk to BB-CUCM. This transformation is done at the Route Group RG-BB-CMS-RMOTE in the Route List Details RL-HQ-CMS-Failover.

For Zoff user located at the BB-Site, the same logic is applied. When the call is sent to the remote CMS HQ-CMS through the SIP Trunk to HQ-CUCM. This transformation is done at the Route Group RG-HQ-CMS-RMOTE in the Route List Details RL-BB-CMS-Failover.

 The second digits manipulation is to strip the prefix « 8 » when the call arrives at the remote CUCM.

For Zico user, once the call with called number 8-882222 arrives at BB-CUCM, the route pattern 8.882XXX wil route the call to BB-CMS, but before sending out the call, we need to strip the prefix « 8 » at the Route Pattern level 8.882XXX using the Discard Digits « PreDot ».

For Zoff user, the same logic is applied, once the call with called number 8-882222 arrives at HQ-CUCM, the route pattern 8.882XXX wil route the call to HQ-CMS, but before sending out the call, we need to strip the prefix « 8 » at the Route Pattern level 8.882XXX using the Discard Digits « PreDot ».

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s