Diversion Header for outbound call forward all calls

[Jonathan136]

The Spectrum voice engineer said the Division header(highlighted below) that Cisco phone system sent to spectrum. This header is causing the problem on their systems. Thus, their system are rejecting the calls. After the Division header removed, all the call forwarding will be working. I can  not find Clusterwide Parameters (System - Call Forward)  under Service Parameter to remove the Division header. I am on CUCM 10.5. 

Could someone help?

Thank you!

[Celso Silva]

You may find your answer at https://community.cisco.com/t5/ip-telephony-and-phones/diversion-header-for-outbound-call-forward-all-calls/td-p/2959514

or https://community.cisco.com/t5/ip-telephony-and-phones/sip-trunk-diversion-header-issue/td-p/2641764

You can remove diversion header from SIP Trunk configuration in CUCM (disable/uncheck Redirecting Diversion Header Delivery - Outbound), LUA / SIP normalization Script applied to SIP Trunk in CUCM ***, or SIP profile configured on your CUBE (or SBC) if you have one between your CUCM and Spectrum.

*** https://community.cisco.com/t5/call-control/sip-normalization-script-to-add-diversion-header-based-on/td-p/3525269

[Jonathan136]

?I will try this and let you know. Thank you.

[Celso Silva]

More information about SIP Normalization Script - https://community.cisco.com/t5/collaboration-videos/a-guide-to-sip-normalization-on-cucm-and-lua-scripting/bc-p/3099495

[Celso Silva]

Call forwarding failing because you are sending Diversion Header? Interesting. After a second thought... I worked with Verizon and other service providers before and we usually need to send the diversion header if the From number is not from one of the numbers we own or have configured with their services. I jump to the conclusion you have a SIP Trunk configured with Spectrum. Can you please share how your SIP Trunk is configured? Do you have a CUBE or SBC between your CUCM and Spectrum?

[Jonathan136]

Thank you for the information Celso! We don't have CUBE between our CUCM( only GW) and Specturm. We use to have windstram(PRI) as provider and never has to do anything with Diversion Header. We started having forwarding issues after our telecom changed provider to Specturm. To answer your question the SIP Trunk is not configured with Spectrum.