Subject: [trill] Ingress replication for multicast forwarding states reduction

From: Mingui Zhang <[email-masked]>
Date: Tue, 19 Jun 2012 07:40:51 +0000

Hi WG members,

In TRILL, distribution trees are pruned per VLAN. The number of multicast states maintained on TRILL switches may be very large.

If RBridges advertise in LSPs that VLANs with _sparse_ multicast receivers would rather use ingress replication, then distribution trees need not be pruned and maintained for these VLANs. Since they are sparse, the bandwidth consumption of them will be low. Given sparse multicast groups may have a high proportion in all multicast groups, the states on RBridges can be greatly reduced. So, whether it's possible to use ingress replication in combination with distribution trees in TRILL?

Thanks,
Mingui