Re: [Sip-implementors] hello message between UA & server

[Paul Kyzivat]

What I described is the mechanism that exists for the purpose. If you find this insufficient, I suppose there are other techniques the server could use to test the liveness of the UA. One that comes to mind is to periodically send an OPTIONS request to the UA. But its not clear to me if that is significantly less costly than sending REGISTER messages at the same frequency.

Paul

Jade Chen Yan wrote:

Paul,

The server should monitors if the UA is online or not. When we use the
expires header , the header should be set no more than 30 seconds.So every
30 seconds, the UA should resend the REGISTER request. And we have millions
of UA registered in our server, in this case, I thought the server's load is
too heavy.I am not sure.

Regards,
Jade

-----Original Message-----
From: Paul Kyzivat [mailto:[EMAIL PROTECTED]]
Sent: Friday, January 10, 2003 10:59 PM
To: jade()
Cc: Sip-Implementors (E-mail)
Subject: Re: [Sip-implementors] hello message between UA & server


Jade,

When a UA registers, the registration has an expiration time. If the UA
fails to refresh the registration before the expiration time, the server
forgets the registration - concluding the UA is no longer present or alive.

	Paul

Jade Chen Yan wrote:

Hi, List,

Since a UA registers to a server, the server should know if the UA is

alive

or not. So every other time, the UA should inform the server that I am
alive. If the server don't get the inform within the time , the sever

should

query the UA if u r online.

I want to know if  any SIP request can fulfill this requirement?


Best Regards,
Jade



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