Techniques for using instant messaging preferences and settings are used for predictive communications, including routing of data traffic, are provided. A voice call can be routed over a packet-based network if a voice network is not available, or for other reasons. In addition to voice calls, embodiments of the invention can route video calls, multimedia communications and other communications. In some implementations, an instant message presence can be queried for in determining how to route a voice-over-IP or PSTN telephone call. Thus, a call might be routed to a computer or computing device unrelated to the location of the PSTN telephone line being called, if an associated instant messenger presence is detected on that computer or computing device.