Run on All Nodes in RL and SIP Trunk

[techToddler]

Hello Friends

I would really appreciate if someone could explain this concept on run on All Nodes in Route List and Sip trunk.  I have seen the blog in cisco support which was explained. But what is the whole concept in two lines. 

Appreciate if someone explain me in plain English with a example. 

Thanks in advance. 

Regards 

Sanjay.

[Ayodeji Okanlawon]

Two lines is difficult..but here is my attempt.

Basically it allows all the cucm servers in the call to be used for outbound calls and it reduces intra cluster communication between cucm servers in the cluster.

[techToddler]

Hello Deji

Thanks for your response first. Appreciate it.

It is not necessary to be in two lines. What I meant is to avoid cisco documentation here which I am not finding easy to understand in few topics.

Okay so all CUCM in a cluster will participate in call processing for outbound. Am I right?

And earlier it was with CM group? So how was this working earlier and now with this feature...

Thanks in advance

Sanjay

[Ayodeji Okanlawon]

You did mention that you read the blog, if you did there is a section on it that explains how things work prior to this feature.

In simple terms yes the CUCM group is used prior to this feature and yes the cucm group is basically ignored with the new feature. But you have to go more into details to really understand it..

So here is an excerpt from the blog I wrote again..

CUCM NODE SELECTION FOR OUTBOUND CALLS

CUCM uses a process called Route Local feature to influence which server is used to initiate outbound calls. This feature selects the CUCM node depending on a number of factors described below:

Using Standard Unified CM Groups with SIP Inter cluster Trunks (PRE-CUCM 8.5)

Before the run on all active unified CM node feature was introduced. The standard behaviour was to use cucm groups with SIP Trunks. There are two scenarios to consider with this type of deployment:

• Route-List in USE
• In this scenario, a Route list is in use and points to one or more Route Groups

NB: The Route List is active only on the primary CUCM in the RL’s Call Manager Group

The cucm node that will be used for a call in this scenario is determined as follows:

When a trunk is used with Route List and Route groups, the Route List is considered to be the calling device.

• If the calling device (Route List) is not registered to a CUCM server that is part of the selected outbound Trunk’s Call Manager Group;
  • Then CUCM will randomly distribute calls across the servers in the Trunk’s Call Manager Group to initiate outbound Trunk calls. This is recommended, because in this scenario calls are load balanced across your CUCM servers.

• If the calling device (Route List) is registered to a CUCM server that is also a server in the selected outbound Trunk’s Call Manager Group;
  • Then use this server to initiate the outbound Trunk call (i.e. the server the RL is registered to)

A word of caution, as you can see this is a bad idea. You do not get any load balancing with this; hence it is recommended that you DO-NOT-CO-LOCATEthe RL and Trunks in the same CUCM group.

Single ICT---No Route List in USE

In this scenario an ICT is in use and the route pattern points directly to it

The cucm node that will be used for a call in this scenario is determined as follows:

• If the endpoint is registered to the same CUCM server that is part of the CUCM group assigned to the sip trunk, then use the server the phone/endpoint is registered to to initiate the outbound call
• If the endpoint is registered to a CUCM server that is not part of the CUCM group assigned to the sip trunk, then cucm will randomly distribute the call across the servers in the trunk’s CUCM group

[techToddler]

Thanks Deji. I read this and was kind of half minded person in understanding few terms. Vivek got it explained in simple terms. Thanks again for your support. (+5)

Sanjay. 

[Vivek Batra · Accepted solution]

Hi Sanjay,

+5 to Chris to share the best document with you and Ayodeji to simplify it in two lines :)

Let say for SIP Trunk, if you don't enable 'Run on All Nodes', respective CM to process outbound SIP request will be selected on the basis of configured CM group. In result, it will increase intra-cluster communication between CM nodes. Let say your phone is registered with CM node 2 which initiates new call and CM group on SIP trunk has priority of CM1, there will be respective intra-cluster communication from CM node 2 to CM node 1 to initiate outbound SIP message.

With 'Run on All Nodes' enabled, CM group is basically ignored and SIP instance runs on all available CM nodes in a cluster. Hence again if your phone which is registered with CM node 2 initiates a call, same CM node (/2 here) can process the SIP message.

Same is applicable for route list as well.

- Vivek

[techToddler]

Thanks Vivek. I got to understand this now. I read the blog again to verfiy everything. Thanks to this forum for all these. 

Sanjay. 

[Vivek Batra]

You're most welcome. Happy to help :)

- Vivek

[Chris Deren]

SRND has good take on it:

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10/trunks.html#pgfId-1335667