Multicast, L2TPv3,EoMPLS support

[uchaudhry]

My requirements are to support Multicast for future deployment and vlan extension over a MPLS ISP( ISP is provding ospf handoff)

I will have to use a software based solution since the tunnel needs to start and terminate on 3845s so L2tpv3 which is router-based solution is a good candidate.

Also EoMPLS does not support multicast I would have to use a GRE tunnel to provide support for multicast.

With MPLS over GRE with EoMPLS feature I am looking at a maximum mtu size of 1570 and if voice is deployed over this then each tiny voice packet will have a pretty big header compared to the header. here i would need to use an additional GRE tunnel for multicast support.

With L2TPv3 it would add 20 bytes of header.

So would l2TPv3 and a gre tunnel for multicast be a good design??

I am thinking using L2TPv3 for layer 2 extension and a GRE tunnel for multicast support.

[ariela]

Hi,

it depends on your multicast application, and topology. Normally I've seen implemented the multicast transport over MPLS cloud in two ways:

1. Multicast over MPLS, using MDT like a GRE tunnel:

http://www.cisco.com/en/US/tech/tk436/tk428/technologies_configuration_example09186a0080242aa8.shtml

2. Multicast over VPLS istance (treated like a broadcast):

http://www.cisco.com/en/US/tech/tk436/tk891/technologies_q_and_a_item09186a00801ed3bf.shtml

Today multicast is not label switched (last Farinacci draft is dated 2003).

HTH

Andrea