[ANCP] Multicast Sub-Capability Definition

[Tom Taylor <tom.taylor at rogers.com>]

I would suggest that the multicast sub-capabilities be defined in terms of 
independent sets of messages and TLVs supported. Once we have done that, we can 
describe their relationships.

I suggest the following sub-capabilities:

a) NAS-controlled replication

Implies support of the Multicast Replication Control message

b) NAS-controlled admission

Implies support of the Multicast Admission Control message

c) Bandwidth delegation

Indication of this sub-capability means that the indicating device supports the 
following messages and TLVs:

Messages:

Bandwidth Reallocation Request
Bandwidth Transfer
Delegated Bandwidth Query

TLVs:

Bandwidth-Delegation-Control
Bandwidth-Allocation
Bandwidth-Request
Bandwidth-Status

d) Shared admission

Implies support of the Multicast-Service-Profile-Name and 
Multicast-Service-Profile TLVs.

I believe a), b) and c) can be implemented independently of each other. d) 
requires b) as a prerequisite.

We can discuss whether support of multicast automatically implies support of the 
 Multicast Flow Query message and Multicast-Flow TLV, or whether this is 
another sub-capability, independent of the other four.