CUCM - SIP Normalization Script

Chidu · ‎04-26-2023

Hello friends, i am very new to this whole things. We are facing issues with SIP communication between CUCM and AudioCodes SBC.

I have a fully functional SIP trunk between these two, however i see the SIP messages are not going correctly.

Complete Call Flow - MS Teams --> SBC (5 digit is forwarded to) --> CUCM (here it decides where to send, either other CUCM cluster or back to Teams, here 5 digit converts to E164 format) --> SBC.

Here when the call comes SBC to CUCM all information are correct but then when it is sending it back to SBC some information are wrongly sent. I have come across the SIP Normalization Scripts helps to fix this. So looking for someone to walk me through

SIP Message is mentioned below -

Thanks in advance.

INVITE sip:+918069xxxxxx@10.xx.xx.xxx:5060 SIP/2.0 --- This portion is correct
Via: SIP/2.0/UDP 10.xxx.xxx.xxx:5060;branch=z9hG4bK1d50954556fe47
From: "Anonymous" <sip:anonymous@anonymous.invalid>;tag=2969613~37e7deac-a6bf-4a44-b5e5-9631f7aa7d3e-27622430 - Here i see 'anonymous@anonymous'
To: <sip:+918069xxxxxx@10.xxx.xxx.xxx>
Date: Wed, 26 Apr 2023 08:03:04 GMT
Call-ID: c41e7180-4481dab8-1c979b-6f0a3f0a@10.xxx.xxx.xxx
Supported: timer,resource-priority,replaces
Min-SE: 1800
User-Agent: Cisco-CUCM11.5
Allow: INVITE, OPTIONS, INFO, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY
CSeq: 101 INVITE
Expires: 180
Allow-Events: presence, kpml
Supported: X-cisco-srtp-fallback,X-cisco-original-called
Call-Info: <sip:10.xxx.xxx.xxx:5060>;method="NOTIFY;Event=telephone-event;Duration=500"
Session-ID: 18d4f7db7ffa4b674177dd9ab1724869;remote=00000000000000000000000000000000
Cisco-Guid: 3290329472-0000065536-0000009568-1862942474
Session-Expires: 1800
P-Asserted-Identity: <sip:+918069xxxxxx@10.xxx.xxx.xxx>
Privacy: id
Remote-Party-ID: <sip:+918069xxxxxx@10.xxx.xxx.xxx>;party=calling;screen=yes;privacy=full

davidn# · ‎04-26-2023

Hi Chidu,

Do you have any specific question regarding LUA scripting or the normalization SIP script that you want to ask?

Regards,

David

Chidu · ‎05-02-2023

hi David, thanks for the response.

My understanding is LUA scripting which helps to correct/modify the SIP headers over SIP trunk.

Here in my case the SIP headers are not populated correctly from CUCM. As shown in the original SIP logs above 'From:' field says 'anonymous@anonymous' which is supposed to be CUCM address. So i am looking for guidance to fix this.

thanks again.

Chida

davidn# · ‎05-02-2023

That's correct. You can use the Cisco Line SDP API to modify the SIP header in the outbound LUA script. There are plenty of example in the documentation:

https://developer.cisco.com/site/uc-manager-sip/documents/sip_normalization_trans/

Hope that help.

Regards,

David

derek555 · ‎05-02-2023

Ensure that both the CUCM and the AudioCodes SBC have network connectivity between them. Check the network settings, such as IP addresses, subnet masks, gateways, and DNS configurations. Confirm that there are no firewall rules blocking SIP traffic between the two devices.