[c-nsp] 802.1w vs EoMPLS failover time

[Walter Keen]

Sorry, our current situation is that during a spanning tree switchover, 
it encounters a buffer underrun error on the RAD box, and we are looking 
to see if perhaps a mpls TE tunnel with explicit paths (2 explicit paths 
plus a dynamic path) would help matters any as opposed to just layer 2 
vlans.  I'll look into FRR.

Phil Bedard wrote:
> The part where you said what the RSTP convergence time was got lost 
> somewhere.  Just using a tunnel primary/secondary paths may not be 
> quicker than RSTP.  If you use FRR protection as well it may result in 
> less traffic loss than RSTP.   Some vendors have different behavior 
> when the failure is on the actual ingress node than a transit node, so 
> you may want to investigate that if you are using FRR.
>
> Phil
>
>
> On Oct 29, 2009, at 7:09 PM, Walter Keen wrote:
>
>>
>> I've got a jitter-sensitive application (voice DS3 over some RAD 
>> equipment) that we are testing, and I've got a rapid spanning tree 
>> ring through the below network.  We have it down to during a spanning 
>> tree switchover (tested by adjusting the rapid-pvst cost on the trunk 
>> interface), and curious if people feel if EoMPLS with a mpls-TE 
>> tunnel would provide faster convergence in case of a failure, given a 
>> fairly vanilla OSPF as the IGP, and 2 explicit paths defined (A-D, 
>> then A-B-D), as the endpoints of this application are at A and D.
>>
>> I think I'm going to start testing this tomorrow or next week, but 
>> curious if anyone had any thoughts or suggestions.  HW is 7600/RSP720 
>> at A and B, 7600/SUP720 at D and C, all with 6724sfp cards for 
>> core-facing interfaces, and 6148 card (10/100) for RAD-facing 
>> interfaces.
>>
>> Network looks like
>>
>> A-------------------D
>> \------B-----------/
>> \----------C-----/
>>
>> Or, A has a connection to D, A has a connection to B and C, B has a 
>> connection to D, C has a connection to D.
>>
>>
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>

-- 


Walter Keen
Network Technician
Rainier Connect
(o) 360-832-4024
(c) 253-302-0194