[SIPForum-discussion] contact field in register

[Victor Pascual Ávila]

Hi Raghul,

On Sat, Jun 21, 2008 at 11:40 AM, Raghul Prasanna <raghul82 at yahoo.co.uk> wrote:
>   In register message I have seen contact fields having parameters like
> contact:sip:aaa at jkhjhj.com
> action=proxy;q=0.9
> contact:mailto:aaa at jkhjhj.com
> q=0.1
>    what do these parameters mean? Can anyone explain?

The Contact header field values of the request typically consist of
SIP or SIPS URIs that identify particular SIP endpoints, but they may
use any URI scheme as Contacts for an addres-of-record: telephone
numbers, email addresses, etc.
More info: RFC 3261- 10.2.1 Adding Bindings

The "q" value is used in the Contact header to indicate the relative
preference of the locations to proxy the request.
More info: RFC 3261- 10.2.1.2 Preferences among Contact Addresses

The "action" value from RFC 2543 indicates redirect or proxy. It has
been deprecated in RFC 3261.

Cheers,
-- 
Victor Pascual Ávila