Network access delays are minimized by using affiliation messages to pre-establish communications in a wireless communication network (100). In a first embodiment, connections between a site and a multicast server are not pre-assigned. A controller (102), upon receiving an affiliation message from a site (104), establishes connections between the site and a multicast server (111), the connections being uniquely associated with a talkgroup/site affiliation indicated by the affiliation message. In a second embodiment, connections between the site and the multicast server are pre-arranged. Thus, responsive to the affiliation message received from the site, the controller informs the multicast server that a talkgroup is affiliated with the site. Regardless of whether the first or second embodiment is used, the multicast server routes packetized information corresponding to the talkgroup to those sites with which the talkgroup is affiliated.