[SIPForum-techwg] comments on PBX-SP v4

[Hadriel Kaplan]

> -----Original Message-----
> From: techwg-bounces at sipforum.org [mailto:techwg-bounces at sipforum.org] On
> Behalf Of Rohan Mahy
>
> Section 8
> propose we add a 4th item.  this was discussed very early, but was
> dropped.  this is consistent with our "do no harm" motto:
> 4) SIP intermediaries MUST NOT modify IP addresses or port numbers in
> the body or Contact header of any message if any of the following are
> true:
> - The SIP message contains an "Identity" header (indicating use of the
> Identity extension)
> - the Content-Type of the body or any of its subparts is
> "application/pkcs7-mime" or "multipart/signed" (indicating support for
> SIP S/MIME)
> - any "application/sdp" body in the message contains any "a=candidate:"
> lines (indicating use of the ICE extension)
> - all the "c=" lines in any "application/sdp" bodies contain only
> public IP addresses (indicating that another element has already
> ensured the addresses are correct).

Define a "SIP intermediary". ;-)  
Then tell me what service goal of this interop specification that service
providers cannot provide to an enterprise or vice versa if they don't follow
the above rule set.  If a service provider or enterprise chooses to use an
"intermediary" because they want to change those message values, for a lot
of reasons, then I don't see a service in this spec they can't still provide
if they want to.  

And "Do no harm" to whom?  Do no harm to their service and network, or do no
harm to IETF drafts du-jour? (well ok, only 2 of those are draft, but all 4
are daft :)  Seriously, though - it's not like vendors of intermediaries
change those fields because it's fun; it's because their service-provider or
enterprise customers want them to, to achieve certain goals.  Any ietf draft
which breaks due to that behavior is not competing against the vendors of
intermediaries - it's competing against their customers' wishes.

It's unfortunate too, because I really like the idea of one of those drafts
(identity) but for some reason it signs the contact, for no identity benefit
I can think of. 

-hadriel