SIP Trunk Mobile Twinning

[malibu1979]

In the test lab, I have a Metaswitch SIP trunk set up for testing and I'm having an issue getting the calling party's caller ID to pass when the call is mobile twinned. Metaswitch rejects the call if they do not see the registered DID in the header and I can not figure out how to send the registered DID and still pass the calling party's caller ID. Any suggestions on how to set this up?

 

[joul]

Depending on the service provider.
But our provider need P Asserted ID to be "Caller" not Original caller, because they use PAI for billing.
- "If there is a PAI it must be a number belonging to the customers number range."
- "If there is no PAI on outgoing call - the (Local URI) From: number must be belonging to the trunk/customer."
But this may not be the case with your line provider.

Also in our example, we need to force the original callers number in the dial short codes: Use the "ss" at the end of the short codes telephone number:
From the Managers manual:
"SS = Pass Through Calling Number Pass through the Calling Party Number.
For example, to provide the incoming ICLID at the far end of a VoIP connection, a short code ? with telephone number .SS should be added to the IP line."
Edit: This is a necessity, especially for Mobile extensions being members of hunt groups, otherwise the receiver will see the hunt group number instead of the original caller.

Example, a IPO 11.1.2 system:

Edit: Also, for the Local URI (SIP From: field) and Contact, You may need to set Forward/Twinning to "Original Caller"

A Dial ShortCode for national calls within +46 SE. (This customer is not using any "line access" dial prefix) :

(Instead of SIP Name/Internal data, we use AUTO and build the URI with Shortcodes and +E.164prefix and "E" to add the extension number
This way we do not need to edit the User SIP name page at all - we use User Rights Shortcodes to ensure the correct E.164 prefix followed by E for extension number)

 

[sizbut]

Metaswitch rejects the call if they do not see the registered DID in the header" - Which header? SIP is all headers and multiple headers can contain URI information. As "joul" is suggesting you may need to adjust the headers sent and which ones contain the called/calling party's details.

Stuck in a never ending cycle of file copying.

 

[joul]

Another example: If this customer doesn't need billing per extension, you could also set a fixed "Explicit" DID, the main number, directly on the P Asserted ID Content.

(this example is using "Internal data" which means that the User extensions SIP Name has to be in correct format. In my case E.164 format +46xxxxxxxxx)

I hope this and my previous example help you understand the SIP headers and how they are used.

Of course Metaswitch may have different rules than my provider, but you see the "mechanics" in IP Office SIP behaviour in these examples.
Your SIP trunk provider may also require some of the other fields in the URI ( P Preferred ID, Remote Party ID )

Refer to the Shortcode section in the manual, your sip trunk provider may also require other charactes ( A or/and i )