Mobile SIP: An Empirical Study on SIP Retransmission Timers in HSPA 3G Networks

Mobile packet-switched voice must replace mobile circuit-switched voice latest with the large-scale deployment of LTE. However, short-term full-area LTE coverage is highly unlikely, handover to and interworking with 3G HSPA networks being a must. This raises the question of how the Session Initiation Protocol SIP performs in today’s HSPA networks.