Re: [Sip] Contact header for PSTN 2 IP call

[Jonathan Rosenberg <jdrosen@dynamicsoft.com>]

The Contact URI can be whatever you want. The only requirement is that 
its globally routable, and when you invoke it, it routes back to that UA 
instance. You need not put the phone number in there if you don't want 
to. The user part can be set arbitrarily at the discretion of the 
implementor. However:

Rosen, Brian wrote:
> Usually it is phonenumber@gateway.com
> There is some work to update the "tel" URI, which would
> probably be used, as in
> tel:+17247426826@gateway.marconi.com
No.

First off, the tel URI has no domain part, i.e., tel:+17247426826. 
Anyway, you cannot use a tel URI since the Contact header MUST be a sip 
or sips URI. It is fine to use sip:+17247426826@gateway.marconi.com, 
however.

> Some gateways need to get a "port" number in there,
> and you occasionally see:
> "7247426826" <port5@gateway.example.com>
> although that is more often found in a From or To rather
> than a Contact.
The meaning of To, From, Contact are well defined in the spec. To/From 
are logical identifiers, and shouldn't be of the form user@host where 
host is a specific device (the gateway, a PC, etc.), but rather, 
user@domain. Contact, on the other hand, needs to reference the device 
as I mentioned above.

-Jonathan R.

--
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
jdrosen@dynamicsoft.com                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors@cs.columbia.edu for questions on current sip
Use sipping@ietf.org for new developments on the application of sip