P-Asserted-Identity Header value in CUCM

[Gordon Ross]

On a SIP trunk in CUCM 11.5, I'm seeing that the P-Asserted-Identity header being sent has the value of:

"LINE_APPEARENCE_DISPLAY_FIELD" <sip:E164MASK@CUCM_IP_ADDRESS>

I need to remove the LINE_APPEARANCE_DISPLAY_FIELD part of this value and just have the SIP URI in there. Looking at CUCM's help and Google, I get the impression that the LINE_APPEARANCE_DISPLAY_FIELD should only be sent if the "Allow Passthrough of Configured Line Device Caller Information" tick box is set on the SIP profile assigned to the SIP trunk. But this tick box is most definitely NOT set for this SIP trunk.

How can I prevent the line appearance display name being sent in the P-Asserted-Identity field?

[Dennis Mink]

Gordon,

just to make sure I understand this, so you want to modify the P-asserted field on a trunk to a CUCM?  does the trunk run into a CUBE so you can use SIP profile to modify the value?

Thanks

[Slavik Bialik]

Try to set "Calling Name Presentation" to "Restricted" in your SIP Trunk settings. And restart your SIP trunk.

Edit:

Ignore me :)

The above will just set the name in the From header to Annonymous.

[Slavik Bialik]

So, again, regarding to my previous comment, ignore it. 

I checked if it's possible via the settings available in the SIP trunk, couldn't find any combinations that will give you that. Maybe missed something, but I didn't find.

Anyway, I wrote you a LUA script that you can use and it'll do exactly what you want:

M = {}
function M.outbound_INVITE(msg)
	-- Get the value of "P-Asserted-Identity"
	local strPai = msg:getHeader("P-Asserted-Identity")

	-- Match the URI out of the whole PAI, and set it to a variable
	local strPaiURI = string.match(strPai, "(<.+>)")

	-- Set the new value into the "P-Asserted-Identity" header
	msg:modifyHeader("P-Asserted-Identity", strPaiURI)
end
return M

Just go to: Device -> Device Settings -> SIP Normalization Script

Add a new one, and enter the above code in it.

After that, go to your SIP trunk settings and select the new SIP normalization script in the "Normalization Script" field.