WebSphere Message Broker supports two different types
of multicast protocol:
- PTL (Packet Transfer Layer)
- PGM (PGM/IP and PGM UDP encapsulated)
PTL provides backward compatibility with WebSphere Business
Integration Message Broker Version 5.0,
where it is the only multicast protocol that is supported. For new multicast
deployments, use one of the two PGM multicast protocols.
The broker supports two implementations of the PGM multicast protocol,
PGM/IP and PGM UDP encapsulated. The complexity of your network topology affects
which option you choose:
- If your network topology consists of two or more subnets with many receiver
clients in each subnet, use PGM/IP. PGM/IP takes advantage of PGM router assist
support.
- For a simpler network topology, use the PGM UDP encapsulated implementation,
which does not use PGM router assist.
Important: To use PGM/IP, both the broker and the
client applications must run with superuser authority. Because of the security
risks that are associated with running with superuser authority, do not run
any other work on the broker.