Abstract: A method of providing multicast communication between a home domain and a mobile device visiting a foreign domain comprises receiving a request to participate in a multicast session from the mobile device and registering the mobile device, from which the request was received, with a sub-session associated with the requested multicast session. The method further comprises providing details of the sub-session to the mobile device; and upon subsequent receipt of a multicast packet corresponding to the multicast session, encapsulating the received multicast packet within a sub-session packet, the sub-session packet comprising the sub-session address as its destination address, and sending the sub-session packet to a care-of address for the mobile device.