Subject: RE: A few questions on REGISTER

From: "Anoop Tripathi" <[email-masked]>
Date: Mon, 27 Sep 1999 10:08:39 -0500

I implement a PBX with one proxy/registrar server and 300 clients(DHCP ) .
All clients send a registration once every 24 hours.

I bring down my proxy server for maintenance.
When I try to bring it back up , I find the registration data is corrupted.
So I cannot resotre the registration information to a state before the proxy was
shutdown.

what do I do to get the system in service.

Go to all the 300 desks and reboot the individual machines.

I think having a  UNREGISTER request is not bad. However, if we have it in the
specification saying a REGISTRAR may silently discard a registration or discard
with a specific UNREGISTER depending upon the implementation .

Thanks,

Anoop

"David Oran" <[email-masked]> on 09/27/99 09:58:06 AM

Sent by:  "David Oran" <[email-masked]>

To:   Anoop Tripathi/MW/US/3Com, "Jonathan Rosenberg" <[email-masked]>
cc:   [email-masked], [email-masked]
Subject:  RE: A few questions on REGISTER

I think some of the confusion has to do with the fact that being
"registered" in H.323 is a very different semantic from being "registered"
in SIP. In SIP, being "registered" is simply telling a SIP server that
you're around and if a call comes in for you where you'd like to get it. In
H.323, being "registered" represents a binding between you and a gatekeeper.
One interesting side effect of this is that in H.323 you are only allowed to
be registered with one gatekeeper at a time (a misfeature IMHO), while in
SIP there's nothing stopping you from registering with as many servers as
you like. This way I can ask both MCI and "Joe's sleazy fly by night find me
follow me service" to direct calls to me if they come in.

So, with H.323 you really need the functionality of knowing when a GK is
about to meet its maker, so you have some prayer of registering elsewhere
when it dies. With SIP, if you want, you can register lots of places.

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]On Behalf Of
> Anoop Tripathi
> Sent: Monday, September 27, 1999 10:09 AM
> To: Jonathan Rosenberg
> Cc: [email-masked]; [email-masked]
> Subject: Re: A few questions on REGISTER
>
>
>
>
>
> >>Why not? Lets say the registration is forcefully expired because of
> >>policy, but the UA is not informed. What behavior in the UA is changed
> >>because of this expiration? (I'd like to avoid feature creep in SIP, so
> >>unless there is an absolutely clear need with a real application, I'm
> >>not convinced).
>
>
> The change of behaviour that I see is the UA might not receive any calls ,
> becuase the Server (Proxy+Registrar) no longer considers it a
> valid endpoint and
> drops all the requests ( with appropriate error responses to the
> originator of
> the call ) intended for this UA.
>
> The UA is unaware of this becuase it thinks it is still registered.
>
> -Anoop
>
>
>
>

---

From: Henning Schulzrinne <[email-masked]>
Date: Mon, 27 Sep 1999 12:24:08 -0400

> what do I do to get the system in service.

Easy: just call up your friend at the local utility company and ask them
for a brief power interruption :-) Or call up your landscaping
department and ask them to install some new flagpoles where the power
line enters your premises. You can also ask our local construction
company for assistance. They seem to have the necessary background in
implementing backhoe fade.

> with a specific UNREGISTER depending upon the implementation .

In that case, an individual UNREGISTER wouldn't do much good since you
don't know who should be registering. I suppose a "hey, I'm a new
registrar (or I can't remember if I'm new or not)" message might be more
productive.

-- 
Henning Schulzrinne   http://www.cs.columbia.edu/~hgs