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Unread 04-18-2007, 11:38 AM   #7
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Originally Posted by martin View Post
You get those bits right and the call will route.
Is that a hypothetical?

What this problem boils down to is that a SPA3102 Gateway sends INVITES with From headers equal to the PSTN caller's CID, instead of its VoIP account. When it's redirected by the destination SIP proxy (such as a SPA942 with Cfwd), it tries to authenticate with this CID. Here is the essential SIP code:

INVITE sip:123456@
Via: SIP/2.0/UDP
From: MOBILE <>
To: <sip:123456@>
Remote-Party-ID: MOBILE>;screen=yes;party=ca lling
Contact: Peer1 <sip:0410000123@>

The Cfwd/REDIR works if there's no incoming CID, or when [PSTN Line]PSTN CID For VoIP CID = No. Effectively this blocks PSTN CID beyond the PSTN gateway, which isn't desireable.

How can PSTN CID and REDIR work together? Is Linksys violating SIP by setting From=PSTN CID, or is Voxalot wrong to authenticate on the From field (presumably not)? How does a Gateway-PBX configuration manage PSTN CID?

I thought of prefixing the CID with a code like 999, but that just throws Voxalot completely.

Originally Posted by martin View Post
I can not answer this question as Voxalot has no visibility whatsoever of the client side
Is that your mission statement?
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