Re: About Path-Resv vs reciever-sender

[Sanjeev Chakravarty <schakrav@ics.uci.edu>]

Hi Reda,

RSVP uses source based routing and yeah the drawback is that each router
needs to maintain a soft-state for the flow. So periodically the
sender(source) sends Path messages to to refresh the state and the
receiver(destination) correspondingly sends the RESV messages. The sender
may decide to adopt a different route becoz of congestion or other reasons
and on receiving the Path message the reciever has to traverse exactly the
same path that the Path message took but in the reverse direction.

Sanjeev Chakravarty
Corona Networks

On Thu, 31 May 2001, Bouarich, Reda wrote:

> Hi everybody,
> Just a quick question to make things clear in my mind. Between a source and
> a client communication,  the source (sender) send a Path message to the
> client (reciever) after a PDP acceptance then the reciever  responds with a
> Resv command.
> I did not understand how the sender know that the reciever has requested a
> communication the first time since that sender is the first actor of the
> communication. I understand that the sender has to send Path message all the
> time to overcome the time out mechanism, but the first time, the reciever
> needs to contact the source to request something, no?
> Any help will be appreciated.
> Thanks a lot.
> Reda.
> 
>