Subject: Re: SIP

From: [email-masked]
Date: Fri, 22 Jan 1999 11:30:22 -0800

One more question about the management capability of SIP and H.323: Even
SIP can use RSVP for some QoS issues. For conference control, SIP can do
nothing, right? Without MC in H.323, SIP endpoints actually don't get any
control information about the conference they are attending, right?  Or
RSVP also can be used for this purpose?

Thanks for any comments!

Hanlin

"Paul E. Jones" <[email-masked]> on 01/21/99 12:45:13 PM

To:   Hanlin Fang/HQ/3Com, "Jonathan Rosenberg"
      <[email-masked]>
cc:   "Aishling" <[email-masked]>, [email-masked]
Subject:  Re: SIP

Hanlin,

This is one of the very issues that I have struggled with.  In the Internet
environment, protocols consume bandwidth as they need.  Latency can be
high,
but it is tolerable.  The idea of introducing voice and video into the IP
network means that there must be some control over the bandwidth, otherwise
the quality of the call (if the call can be placed at all) will suffer.

Imagine this scenario:  an earthquake strikes California.  Everybody in the
state and out of the state attempts to place calls in and out of the
earthquake zone to check on friends and family.  Today's telephone
equipment
will allow a certain number of calls to succeed-- all other attempts will
fail due to busy circuits.  With the use of SIP in an IP telephone device,
there is nothing (that I can see) that would prevent everyone from
attempting to place calls simultaneously.  The end result is that all of
the
calls would suffer to the point that nobody could understand anything said
on the call.  Something must control the traffic.

Surely the SIP designers have planned for this scenario.  I would love to
know how the situation would be handled in a SIP environment.

Best Regards,
Paul

-----Original Message-----
From: [email-masked] <[email-masked]>
To: Jonathan Rosenberg <[email-masked]>
Cc: Aishling <[email-masked]>; [email-masked]
<[email-masked]>
Date: Wednesday, January 20, 1999 12:34 AM
Subject: Re: SIP

>My question is that: if you don't use proxy server in SIP, how can you get
>control and management capability comparing with H.323 gatekeeper system?
>If you use proxy server model, is there any significant difference between
>H.323 and SIP?
>Thanks for any comments!
>
>Hanlin
>
>
>---------
>This message came from the IETF IPTEL Working Group Mailing List.

---------
This message came from the IETF IPTEL Working Group Mailing List.