Re: [Sigtran] Number of links towards a DPC (ITU)

["David Laight" <[e-mail]>]

> Satya,
> 
> Nemana, Satya wrote:                    (Mon, 17 Jun 2013 15:27:13)
> > My 2 cents.
> >
> > The ITU spec may not say this, but why not do this.
> >
> > 1) Use the LSB to select the linkset within a combined linkset.
> 
> So, XXX0 goes to one linkset and XXX1 goes to the other.
> 
> > 2) Once the Linkset is selected, use the full SLS value to select one
> >    of the links in the linkset.
> 
> On the first linkset, the entire SLS is XXX0.  There are only eight
> values here.  On the second linkset, the entire SLS is XXX1.  There
> are only eight values here.  So, 8 links per linkset, 16 links per
> combined linkset.

That just means that the traffic to that destination can only use 8 of
the links in the linkset - even if there are more.
So it might not make much sense to have 16 links in both linksets,
but that doesn't mean that it isn't allowed.

Consider the following network fragment:
Endpoint A has a linksets with 16 links to both B and C (SEP + STP).
Additionally A has routes to SEP D via both B and C.
Traffic to B will use all 16 direct links (backup route via C).
Traffic to D will loadshare between B and C, but will only use
16 of the 32 possible links (ideally 8 via B and 8 via C).

(Wonders what our MTP3 does when configured to evenly distribute
the sls across all the links ...)

	David