[SIPForum-techwg] Spec-T, Trust

[Cullen Jennings]

When discussing the PAI, I think you have to come down on where the  
trust boundaries of the Spec-T are or it is impossible for anyone to  
deploy in a way that is secure yet still actually work. I suspect that  
from a spec-T point of view, you will need to say that the PBX trust  
the SP but but the SP does *not* trust the PBX. One you make this  
decision, I think you need to relook at who uses the PAI and where and  
when then from decide where to insert it.

Keep in mind that many jurastiction will require the SP to support  
malicious call trace of anonymous calls. If you skipped over that last  
sentence quickly, go read it again, it has bit implication for the use  
of PAI.