> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of
> Cullen Jennings
>
> I actually don't think that is the case. My recollection, could be
> very wrong, what that SER edits outbound, not inbound SDP. That said,
> if SER editing my inbound SDP, it would check the signature before
> doing so, and then go and execute my black list that rejected calls at
> 2 am form people other than a certain set, then send the call down to
> me. Once again, I not getting what is broken in this case.

1) If the call goes to another SER in another domain that is fixing NAT for its 
UAS, then that SER will edit the SDP before sending it to the UAS (or at least 
if it's doing what SBC's have been doing for many years).  If that SER is the 
verification service then sure it can do as you say, instead of letting the UAS 
verify it.  But maybe they want to let the UAS make its own decisions. (crazy 
guys!)

But as we've talked about before, that is just the tip of the iceberg because 
changing SDP for NAT traversal is only one of a long list of reasons for 
changing SDP.  And in most cases we're not talking about only the UAS not being 
able to verify - we're talking the last/terminating domain as a whole being 
unable to verify. (which was kinda the point of it I thought)  So to continue 
the list of cases...

2) If the call goes to a 3PCC server that holds onto SDP when it forwards on 
the INVITE, then the signature breaks.

3) If the call goes to a transcoding element that modifies the SDP codec list 
when it forwards on the INVITE, then the signature breaks.

4) If the call goes through transit providers 
(long-distance/wholesale/international), then often SDP gets changed and the 
signature breaks.

5) If the call goes from an Enterprise PBX over a SIP Trunk to a provider, and 
they route the invite to another Enterprise PBX, then often SDP gets changed 
and the signature breaks.

6) If the call goes from an Enterprise PBX over a SIP Trunk to a provider, and 
they route the invite to a mobile-phone provider, such as a GSMA-IPX one, then 
often SDP gets changed and the signature breaks.

7) If the call goes from an Enterprise PBX over a SIP Trunk to a provider, and 
they route the invite to another provider, then often SDP gets changed and the 
signature breaks.

8) If the call goes from a provider over a SIP Trunk to an Enterprise PBX, and 
the PBX routes the invite to a branch office over a VPN, then often SDP gets 
changed and the signature breaks.

9) If the call goes from a branch office over a VPN to an Enterprise PBX, and 
the PBX routes the invite over a SIP Trunk to its provider, then often SDP gets 
changed and the signature breaks.

10) If the call goes from anyone anywhere, to anyone who could actually benefit 
from something like 4474 instead of simply using PAI, then often SDP gets 
changed and the signature breaks.

-hadriel
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