Subject: Question for the RFC2961--Refresh reduction--trigger msg

From: "Hong Liao" <[email-masked]>
Date: Mon, 10 Mar 2003 11:57:19 -0500

Hi,

I have question for the trigger message.

In the RFC2961,section 4.5,

>>When a node is sending a trigger message, the Message_Identifier value
MUST have a value that is greater than any other value previously used with
the same Epoch field value.

so basically if it is a trigger message then message id should be greater
than previous one with the same epoch value;but does this mean that if the
message id is greater than previous one for the same epoch value, and the
rest of the contents are the same as the previous message, then should the
message be considered as trigger message ?  Can someone confirm this for
me?

Thanks in an advance.

Hong (Julia) Liao
ATM/Broadband Network Integration
Telcordia Technologies, Inc

Tel:  (973) 829-4570
Fax: (973) 829-5962

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From: Ping Pan <[email-masked]>
Date: Mon, 10 Mar 2003 13:13:50 -0800

Hi,

A couple of points:

1. What qualify as a trigger message on a receiving node?

The idea of refresh reduction is to avoid looking at the content of the 
message. Thus by looking at the message-id, the epoch value, and 
RSVP-hop (that is, incoming interface, RSVP phop address), if there is 
no match to your local table, this is a trigger message. Process the 
message in detail.

2. Why incremental message-id's?

For mis-ordering. When processing a message that carries a message-id, 
from SESSION and SENDER_TEMPLATE, find the flow entry first. If the flow 
entry records a message-id greater than what you have received, don't 
process the message - because this is an old junk. (Actually, I didn't 
see this condition in a customer's test net.)

To make sure you are OK with the msg-id roll-over, the routers always 
change to a new epoch number and start to assign messag-id from a small 
value again.

Hope this will help.

- Ping

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From: David Charlap <[email-masked]>
Date: Mon, 10 Mar 2003 17:27:13 -0500

> change to a new epoch number and start to assign messag-id from a small 

I'm not sure I understand you here.

When do they always change to a new epoch number?  When the value hits 
the maximum?  Or at some other time.

I don't recall this being a requirement.  The requirement that I saw was 
that routers must be able to detect and support rollover.  A code 
fragment was provided to show developers exactly how to do this, so 
there shouldn't be any excuse for a router that doesn't detect this.

-- David

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From: Ping Pan <[email-masked]>
Date: Mon, 10 Mar 2003 14:30:58 -0800

David Charlap wrote:
>> change to a new epoch number and start to assign messag-id from a 
>> small value again.
> 
> 

When it is approaching the max. for rollover.