Apparatus, system and method for managing call requests in a communication network providing a plurality of communication services

Information corresponding to a half duplex voice call over a packet network is delivered to unavailable members of a group through alternate communication services. A call request for half duplex voice calls over a packet network is received at a communication server where the call request indicates a group. Packets corresponding to the voice call are converted into an alternate formatted message and delivered, through an alternate communication system, to unavailable members of the group not able to engage in the voice call at the time of the call. The alternate formatted message such as Instant Messaging (IM) message or voice mail message is delivered to the unavailable member when that member is able to receive such a message.