The MPLS WG Archive

[David Charlap <david.charlap@marconi.com>]

Jie Zou wrote:
> 
> In RFC 2205, section 2.3
> 
> 1. "When the received state differs from the stored state, the stored
> state is updated.  If this update results in modification of state
> to be forwarded in refresh messages, these refresh messages must
> be generated and forwarded immediately, so that state changes can
> be propagated end-to-end without delay."
> 
> Seemly, refresh message can be different with the Path message sent
> before. In my opinion, it should be a new Path message and we don't
> need to change the state(just store it).

It depends on what differs.

If the SESSION and SENDER objects are different, then the message is
signalling a different path.

If the SESSION and SENDER objects match those for an existing path, then
the message serves to update that path.  Either a refresh (if everything
matches) or an update (if something changed).

> 2. Is there some standards for the refresh timeout period like 5 ms,
> etc?

The only reference I know of is in RSVP 2205, section 3.7.

The author suggests a refresh period of 30 seconds between outgoing
refreshes.  He also suggests that incoming messages should expire if
three refresh intervals (based on the TIME_VALUES of the last incoming
message) pass without a refresh.

He also says that these values should be configurable, because some
networks will prefer other values.

-- David