Subject: RE: Between OSPF RSVP...

From: "Ferrell, William" <[email-masked]>
Date: Mon, 17 Mar 2003 09:07:30 -0500

Steve 

I ask a simple question or two. 
1. how detrimental could this be to our MPLS implementation and 
2. What should we do to mitigate the risk ?
Will

-----Original Message-----
From: Steve Yao
To: [email-masked]'
Cc: mpls
Sent: 3/14/03 12:51 PM
Subject: RE: Between OSPF RSVP... 

>Steve,
>
>In two messages prior you stated:
>
>> The RRO received at the HE only contains the IP addresses 
>that map to half
>> of the LSAs or LSPs that the LSP traversed. 
>
>You mentioned that only half the LSA/LSPDU were in the RRO, so the
>question "What cases were you thinking of?" that you just asked should
>be directed to you.

I asked the question since you mentioned earlier:

>It wasn't intended to cover all cases and does not depricate use of
>path-tear.  You still didn't answer my question.

But it is ok if you don't want to answer the question.

>
>Since you brought up the issue "where RRO may be too large" why don't
>you do the math and tell us 1) how big the RRO would have to be to be
>too large and 2) how likely you think that is of occurring.  RSVPd
>objects can be 64KB each.  The IPv4 address subobject is 8 bytes long,
>including type and length.  Add a label subobject (8 bytes) and fit it
>into a reasonable MTU and you're still at hundreds of hops.  I get
>200+ into a 4KB MTU and most networks seem to be going for 8K MTU so I
>get "not very likely" for question 2).
>
>Curtis
>

I agree that this is not very likely.

Steve
 <<ATT77972.txt>>

---

From: Curtis Villamizar <[email-masked]>
Date: Mon, 17 Mar 2003 10:37:08 -0500

In message <561621C69F17D511A3A20050047340EC01AAF610@VCMD-NT1>, "Ferrell, Willi
> 2. What should we do to mitigate the risk ?

Will,

What is "this" in your question?  If it partially filled RRO, we
determined it not occur except for certain conditions that are
entirely a matter of network design (such as interarea).  We also
concluded that even if the RRO was partially filled, the path-tear and
notify (if used) would handle tear down and initiate reroute.

Please be more specific in your question, if I haven't answered it.

Curtis