Subject: [6tsch] Routing vs. switching

From: "Pascal Thubert (pthubert)" <[email-masked]>
Date: Sat, 1 Jun 2013 01:15:14 +0000

Dear all ;

We had a great discussion today at the weekly call about routing that relies on 1 hop cell bundles vs. switching that operates on end to end tracks.

We agreed that merging and splitting tracks could require queuing at intermediate nodes to absorb burst collisions from multiple sources and decided to go for the watertight pipes.

We proposed 2 additional strategies:

a) define a multicast mac address for the track, so we can 1) reuse a track cell that is not used by a deterministic packet for hop by hop L3 traffic as differentiated by its unicast MAC destination and 2) forward with no change to the destination.

b) let the PCE install routes as well as tracks. With that strategy, A PCE route is an alternate to a track that would allow cell reuse and L3 QoS operation. We leverage the deterministic Class of service (that's Deterministic Forwarding, DF, though encoded 0xEF). And we can emulate RPL local instances as indexed by the tuple (source address, local_instance_id) and forward the packet with the same rules are RPL, along the routing table indexed by the instance ID.

Comments welcome!

Cheers,

Pascal