Determination of SIP transport to reduce call setup delays

Methods, apparatuses, and systems are presented for determining an appropriate transport protocol for supporting Session Initiation Protocol (SIP) communication, which may involve repeatedly sending SIP requests from a first device destined for a second device using at least one transport protocol, attempting to receive responses to the SIP requests at the first device from the second device, based on results of attempting to receive responses to the SIP requests, updating a data record associated with the first device, the data record containing an entry for the second device, the entry for the second device including at least one indication of operability with the at least one transport protocol, and selecting one of the at least one transport protocol, based on the entry for the second device in the data record, as a selected transport protocol for establishing a desired SIP communication between the first device and the second device.