[SIPForum-discussion] Contact header field in REGISTER request

[Paul Kyzivat]

On 12/21/13 12:06 PM, Vijay Kumar wrote:
> Hi all
> Usually  contact header field in a REGISTER request contains
> Contact:<sip:bob at IP address>
>
> Can there be a Contact header field
> like Contact:<sip:IP address> without user-info part ?
>
> There is no much in RFC 3261.
> Is there any format of Contact header field with Mandatory parameters

As far as the sip protocol is concerned you can put any syntactically 
valid URI in the Contact of a REGISTER.

It doesn't even need to be a sip URI. (E.g., You can put a mailto: URI 
if you want. But I suspect not all registrars will allow this.) Of 
course non-sip URIs won't be useful for dispatching SIP requests.

But certainly *any* valid sip URI should be allowed, unless your 
registrar is restricted to a specialized environment where it exerts 
tight control over the sorts of endpoints that can register.

	Thanks,
	Paul