> -----Original Message-----
> From: Sambhrama Mundkur [mailto:[EMAIL PROTECTED]]
> Sent: Saturday, December 02, 2000 3:50 AM
> To: [EMAIL PROTECTED]
> Subject: REGISTER message
>
>
> Hi
> I was trying to implement a Registration server for SIP.. I had the
> following doubts about the the ttl (expire time)
>
> * When we need to delete some registration from the server,
> do we check if
> we have to delete just the per-contact information (after it
> crosses its
> ttl) or the entire user information .
Each contact has a separate TTL (aka expiration).
If the second case applies, what
> happens if the Expire ttl is lesser that some contact ttl, we still
> delete all information about the user??
The spec specifies a priority ordering of expriations. A per-contact
expiration overrides the Expires header value when specified.
>
> * Is it an error to get a REGISTER request with no contact headers?
No. This is used as a query to find the current set of registered contacts,
since the response to REGISTER always contains the current set.
>
> * What if for a particulat contact the expire time is not
> specefied. Do we
> use the time from the Expire header (or if the Expire header
> is not there,
> the DEFAUKT ttl)
>From Section 6.13:
expires: The "expires" parameter indicates how long the URI is valid.
The parameter is either a number indicating seconds or a quoted
string containing a SIP-date. If this parameter is not provided,
the value of the Expires header field determines how long the
URI is valid. Implementations MAY treat values larger than
2**32-1 (4294967295 seconds or 136 years) as equivalent to
2**32-1.
The default value, if neither Expires or the expires Contact header is
present, is one hour. From Section 4.2.6:
A server MAY choose any duration for the registration lifetime.
Registrations not refreshed after this amount of time SHOULD be
silently discarded. Responses to a registration SHOULD include an
Expires header (Section 6.20) or expires Contact parameters (Section
6.13), indicating the time at which the server will drop the
registration. If none is present, one hour is assumed. Clients MAY
-Jonathan R.
---
Jonathan D. Rosenberg 72 Eagle Rock Ave.
Chief Scientist First Floor
dynamicsoft East Hanover, NJ 07936
[EMAIL PROTECTED] FAX: (973) 952-5050
http://www.cs.columbia.edu/~jdrosen PHONE: (973) 952-5000
http://www.dynamicsoft.com
