sip trunk css and route pattern query?

[baselzind]

im trying to wrap my head around the css and route pattern partition used with the sip trunk , i noticed that when creating a sip trunk i choose a css under the incoming calls , as the sip trunk connecting two different cucm networks how is the css relevant here? does the css here means that any incoming calls from the sip  trunk can call phones partitions under that css ???

also under the route pattern for numbers called through the sip trunk , the "route partition" here means phone that can call that specific partition can call through this sip trunk?? please correct me if im wrong?

[HARIS_HUSSAIN · Accepted solution]

Hi,

The CSS under the SIP Trunk is for Incoming Calls, i.e the call which will come to CUCM from External Device to which this SIP Trunk is pointing.

Say If you created SIP trunk to Ip 10.1.1.1 then calls coming form that IP will have This CSS.

usually  assigned Internal_pt to allow dialing to all extensions.

Below is a Snapshot

For The Partition on Route Pattern,

It is used for Outbound Calls for Devices Registered To CUCM.

So if The Route Pattern pointing to SIP Trunk is in Partition Say PT_TRUNK

then all devices having access to PT_Trunk and dial using the SIP Trunk.

Please rate if found useful.

Thanks

Haris

[baselzind]

thank you for you explanation but regarding route pattern partition , u meant that only devices that can call PT_Trunk can use this route pattern to call through this sip trunk?

[HARIS_HUSSAIN]

Yes that is correct.

Say you want to route Patten  7XXX with Route Partition PT_Trunk Pointing to SIP-Trunk.

If Phone-A has CSS_phone ( with PT_trunk in It) then PHone A can dial 7XXX and call will be routed to SIP Trunk .

Thanks

Please Rate or Mark Correct if found useful.

[Les Pruden]

Correct -

If the CSS of the calling device does not contain the partition of the route pattern the call will not complete.

Phone A - CSS = (PT_Trunk) -- -- Route pattern 10000 - Partition = PT_Trunk -- route to SIP trunk   <-- this call works

Phone B -- CSS = (PT_Internal) -- -- Route pattern 10000 - Partition = PT_Trunk -- route to SIP trunk   <-- this call does not work

[Jaime Valencia]

CSS and partitions work basically the same as they do in a phone.

The partition you define in the RP is the same as if you were setting  it on a DN. Who can call you.

The inbound CSS is the same as if you were setting the CSS in a DN or phone. Who you can call.

That's why there's a DNA option for trunks, in the end, they're just relaying what they get, but working within CUCM as if they were just another endpoint to place calls (with a few more options to do digit manipulation). 

If you don't have a good understanding of how CSS and partitions work, you really should be reviewing the dial plan chapter from the SRND, the calling privileges section that Les mentioned.

[GaneshB]

It helped me. Thanks!

[Les Pruden · Accepted solution]

You've got it more or less correct. 

Partitions - who can call you

CSS - who you can call

You can read the --> Calling Privileges in Unified CM <-- section of the SRND for a more detailed explanation with examples.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10.pdf