The MPLS WG Archive

[Steven Berson <berson@isi.edu>]

On Thu, 27 Jul 2000 Ted44tedT@netscape.net wrote:

>   I have several questions about the RSVP and RSVP-TE:
> 
>   If a host want a resource reservation, it should send Resv message toward
>   the sender first, right? and then the sender send back Path
>   message back ,right?

This is not correct.  In RSVP the sender first sends a PATH message.  
Then the receiver sends a RESV message.

The PATH message serves as an announcement of the sender being ready
to source data.  It also provides the proper route of the data which
the RESV message follows back to the source.  Finally, the PATH
message provides an ADSPEC which has information about the quality of
service the receiver can reserve.
 
>   But in RSVP-TE(06.txt), the sender should send the Path message first toward the receiver,
>   and then the receiver send back the Resv message. When the sender receive the Resv msg,
>   the LSP is setup.
> 
>   I think the RSVP is a receiver-oriented protocol, so the receiver should send the Resv msg
>   first toward the sender in the RSVP-TE(06.txt) to setup the LSP.
> 
>   I know I was confused by some points. But I don't know where.
> 
>   Sincerely,
>   Ted