The MPLS WG Archive

[Steve Yao <syao@chiaro.com>]

Hi Will,

Whether an RRO can fit into a Path/Resv message is dependent on a
combination of various factors including, for example, large private
objects. However, at this point, it appears that the likelihood of such a
scenario is low.

Steve


>-----Original Message-----
>From: Ferrell, William [mailto:William.Ferrell@titan.com]
>Sent: Monday, March 17, 2003 10:49 AM
>To: 'Curtis Villamizar '; Ferrell, William
>Cc: ''Steve Yao ' '; ''mpls ' '
>Subject: RE: Between OSPF RSVP... 
>
>
> 
>Steve
>Yes , you hit the nail on the head .. That was the "this"
>In essence we're saying that risk is mititaged through 
>effective design and
>numeric improbability, right.
>Will
>
>-----Original Message-----
>From: Curtis Villamizar
>To: Ferrell, William
>Cc: 'Steve Yao '; ''curtis@fictitious.org' '; 'mpls '
>Sent: 3/17/03 10:37 AM
>Subject: Re: Between OSPF RSVP... 
>
>
>In message <561621C69F17D511A3A20050047340EC01AAF610@VCMD-NT1>,
>"Ferrell, Willi
>am" writes:
>>  
>> 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
>
>
>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
>
>
>
>> -----Original Message-----
>> From: Steve Yao
>> To: 'curtis@fictitious.org'
>> 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>> 
>> 
>
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