Subject: [6tsch] 6tus layer

From: Xavier Vilajosana <[email-masked]>
Date: Fri, 19 Apr 2013 09:15:18 -0700

Hi, I'd like to follow up that discussion..

My point is close to Pascal's point, i.e 6tus is a similar "thing" as 
GMPLS as 6tus can decide on switching or forwarding according to the 
time slot when a packet comes in. That mapping of input slots/output 
slots in GMPLS is done by a reservation protocol that is specified by 
the GMPLS layer (Label Distribution Protocol) and implemented by a 
higher end-to-end protocol like RSVP-TE. In that sense we can see 6tus 
as the same, an entity that runs on layer 2.xx and knows about time 
slots and when a track is scheduled knows when (what time slot) has to 
be used to forward a packet coming at a specific time slot.

what are your thought?

X

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From: "Qin Wang" <[email-masked]>
Date: Fri, 19 Apr 2013 18:52:09 -0700

Pascal and Xavi,

I agree that the behavior of 6tus looks like GMPLS in terms of forwarding
data packets. But, it seems to me that GMPLS uses Label in packet to
"replace" IP address in selecting next hop, that meets the encapsulation
criterion of Layering. But, 6tus does not function in this way, i.e. it
selects the cell and next hop according the TSCH schedule in local.
Correct?

Qin

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From: Xavier Vilajosana <[email-masked]>
Date: Fri, 19 Apr 2013 19:01:53 -0700

Hi Qin,

GMPLS does not use in-packet labels, the labels are known at each node 
and the switching is done according to the input time-slot which is 
matched to an output time slot (this applies also for lambda switching 
and wave-length switching supported by GMPLS). So I think that our 
concept is the same, 6tus works on the schedule and can know what slots 
are used to send to the next hop in the track, therefore if we consider 
that 6tus have to deal with switching of packets it is a feature that we 
can address easily.

cheers
Xavi