The MPLS WG Archive

[Shahram Davari <Shahram_Davari@pmc-sierra.com>]

Curtis,
 
> The rate should be configurable.  If you want to fix it at one second
> in your network you can still do so.  


Being configurable is different than being variable ! You were arguing
that the ingress should vary its rate.

> 
> > -	you can decouple source/sink processing (might not be obvious
> > why.....but here are some pointers:  CV is unidirectional 
> (for good reasons
> > as explained why by several people already).  CV generation 
> is trivially
> > easy.  Some LSPs don't need CV *monitoring*, ie unimportant 
> ones (possibly
> > potential candidates for Ping).  CV can detect more than 
> simple breaks, like
> > various misbranching/merging/config cases and immediately identify
> > offender.....and if you have some important customers whose traffic
> > integrity needs protection this might be considered quite important)
> 
> Your first point is ragarding efficiency.  There is no strong argument
> for putting the load on the egress.  Not having any feedback to sender
> is a poor design.  We can agree to disagree on this.


It is fairly obvious that the BW usage in LSP-ping method is double of the
Harrison's proposal. And as Dave McDyson mentioned BW usage is an important 
factor. It seems redundant to me, to feedback the information to the source, 
when there is no problem.


> Current hardware does not remember the prior label after it is popped,
> so there may be a problem identifying the LSP after inspecting what is
> underneath it.  For that we made need to limit TTL, recognize the the
> bottom label is special (whether MPLS-OAM or IPv4 Explicit Null) and
> process according to the banished TTL expired rules.
> 

This problem is solved easily in Harrison's draft by using a TTSI identifier.

-Shahram