[zeromq-dev] pub/sub and multicast

[McMillan, Scott A]

Hi,

Sorry for the very basic question, I'm new to zeromq.

The FAQ (http://zeromq.org/area:faq#toc0) says "PUB does multicast."  How
should I interpret this statement?  Does this mean that IP-level multicast
is required to use the pub/sub pattern?

Looking at the examples, it looks like the protocol can be selected
independently from the pattern?  E.g., several examples contain the
following, which I interpret as the pub/sub pattern on top of TCP unicast:

  void *publisher = zmq_socket (context, ZMQ_PUB);
  zmq_bind (publisher, "tcp://*:5563");


If one wanted to use multicast, then the second line would be replaced
with something like:

  zmq_bind (publisher, "pgm://...");


Am I understanding this correctly?

Thanks,
Scott