We just keep the connection open for a little time (30 seconds or so).
In many cases a new transaction to the same destination needs to be done
and then it's already open. This speeds up communication and causes
little headache.

CS
--
Dr.-Ing. Christian Stredicke
sip:[EMAIL PROTECTED]

> -----Urspr�ngliche Nachricht-----
> Von: [EMAIL PROTECTED] [mailto:sip-implementors-
> [EMAIL PROTECTED]] Im Auftrag von Prithi Shetty
> Gesendet: Mittwoch, 22. Januar 2003 08:00
> An: James Ford; [EMAIL PROTECTED]
> Betreff: Re: [Sip-implementors] Closing TCP connections
> 
> Hi James,
> 
> TCP std does specify about connection closing, called
> "four-way close connection".
> Here, side X sends a FIN, to indicate that he has
> nothing to send. The other guy Y receives this FIN and
> sends an ACK. X sends an ACK on receiving Y's ACK.
> Thats when  the connection actually closes
> 
> TCP provides the ability for one end of the connection
> to terminate its output, while still recving data from
> the other end. This is called a half-close.
> In case of client-server scenario, if client sends
> FIN, and server still has data to be sent, then server
> sends an ACK and continues to send the data. After
> server is done with transmitting data, it sends a FIN
> and waits for ACK. When client sends the ACK,
> connection is closed.
> 
>      Client           Server
>       |               |
>       |-----FIN------>|
>       |               |
>       |<----ACK-------|
>       |               |
>       |               |
>       |<----DATA------|
>       |               |
>       |               |
>       |<----FIN-------|
>       |               |
>       |-----ACK------>|
>       |               |
> 
> In case, server wants to close, it sends FIN and waits
> for ACK. Since client has nothing else to do, it
> replies an ACK, sends FIN and waits for the ACK. Upon
> client receiving ACK, connection is finally closed.
> 
> So now the SIP programming interface must provide a
> way for the appln to say "I am done sending data,so
> sending FIN to the other end. But I still want to recv
> data from the other end, until it sends me FIN".
> 
> Regards,
> Prithi.
> 
> --- James Ford <[EMAIL PROTECTED]> wrote:
> > Hi,
> > Does the SIP standard specify who is responsible for
> > closing tcp connections
> > (client/server)?
> > To be more specific if a server transaction closes
> > its TCP connection before
> > termination it will be
> > impossible to keep a persistent connection open to
> > an outbound proxy for
> > example.
> > Thanks,
> > James.
> >
> >
> >
> >
> >
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