Call Flow information

[josepaulopetry]

Hello,

Where can i find info on how call flow works on CUCM?

For example, i want to know the info bellow, where can i find it?

User A calls User B. They are using G729 because they region config.

Then User B transfer the call to User C, so User A and User C start talking... but they region's config is to use G711... so they will use G711, right?

Where can i find a Cisco Doc about how will this (and others) call flow work??

[Chris Deren]

This is all based on how you configure CUCM, for best practice design check out Cisco Communications Manager SRND doc for your CUCM version.

HTH,

Chris

[josepaulopetry]

sorry, i didnt found this info at SRND

[Chris Deren]

Well, SRND is a guidance on what you might want to use, but ultimately it is the design engineer's job to design it to use proper codecs and build respective Regions.  By default this CUCM service parameters define that intra-region calls will use G711/G722 and inter-region calls will use G729, you can either uses these defaults and not make any changes to Regions as you build them, or you can define other codecs within and between regions.

Chris

[josepaulopetry]

ok..

but do you know any doc that says how are the call flow??

I mean in the case of a transfer call... something that says:

Rings User C phone

Check Region config

Negotiate Codec

User C answers

Start Media

etc etc etc

Having this info (how thing should works) turn easier the troubleshooting process when analyzing debugs for example..

[Jaime Valencia · Accepted solution]

this might help, but honestly, the best way to learn that is to actually pull some traces out from a successfull call (whatever you're trying to figure out how it works) and read them to understand how they should look

SCCP Call Flows

http://www.cisco.com/en/US/partner/docs/voice_ip_comm/cata/186_188/2_15_ms/english/administration/guide/sccp/sccpaaph.html

HTH

java

If this helps, please rate

www.cisco.com/go/pdihelpdesk

[Leonardo Santana]

Hello Jose,

For example if you want to know this you need to see the SRND, if you want no know about location and regions see the section about CAC..

[Chris Deren]

Sure, this is controlled by the protocol you are using, i.e. SIP or SCCP, all media capabilities, etc are negotiated between the phone and CUCM via INVITE message for example with capabilities defined in SDP message with SIP. So, if you understand SCCP and/or SIP call flows you understand how this works.

HTH,

Chris

[josepaulopetry]

thanks