The MPLS WG Archive

[Rajesh P Jain <rpjain@sasken.com>]

Hi,
                    I have some doubts on Smooth Re-Routing of LSP
Tunnels.

1. As I understand the draft, the make-before-break (Smooth Re-Routing)
should be initiated by the Sender Node (Path Message is sent new with
new ERO object and ofcourse with a different LSP ID in the
SENDER_TEMPLATE ). The receiver receives this Path Message.

2. Now, the receiver HAS to send a RESERVE message with SE reservation
style (Of course with Filter spec list containing the SENDER_TEMPLATE of
the old Path Message and SENDER_TEMPLATE of new Path Message i.e they
differ only in their LSP ID's, and of course ERO's).

3. Now, the New Path Message received  is AS GOOD AS A New Sender for
this receiver and hence it MAY NOT send a RESERVE Message for this
sender (The receiver sends only if it wants some reservation for this
sender).

4. In case, if the receiver chooses not to send the reserve message,
then Smooth Re-Route WILL NOT happen.

                    So, can anyone explain whether the Smooth Re-Routing
is Sender-Based  or Receiver -Based (Who has the control of Re-Routing
the traffic ??) ???

                    In case of Increase in Band-width (For a particular
LSP), the Sender indicates the increase in band-width BUT still the
Receiver HAS to send the Reserve message for this increase in the
Band-width. So, the same problem holds good for this case also????

                    Am I missing something???? Please throw light on
this issue possibly with an example.

TIA
        Rajesh P Jain