TITLE:
The Overload Reduction in SIP Servers through Exact Regulation of the Retransmission Timer of the Invite Message
AUTHORS:
Ahmadreza Montazerolghaem, Mohammad Hossein Yaghmaee
KEYWORDS:
Reduction of Session Initiation Time; SIP (Session Initiation Protocol); Invite Message Retransmission Timer; Overload Reduction
JOURNAL NAME:
Journal of Computer and Communications,
Vol.1 No.2,
May
30,
2013
ABSTRACT:
To initiate
voice, image, instant messaging and general multimedia communication, the
Session communication must initiate between two participants. SIP (Session
initiation protocol) is an application layer control, which task is creating
management, and terminating this kind of Sessions. With regard to the independence
of SIP from the Transport layer protocols, the SIP messages can be transferred
on a variety of Transport layer protocols such as TCP or UDP. The mechanism of
Retransmission, which has been embedded in SIP, is able to compensate the
missing Packet loss, if needed. The application of this mechanism is when SIP
messages are transmitted on an unreliable transmission layer protocol such as
UDP. This mechanism, while facing with SIP proxy with overload, causes
excessive filling of proxy queue, delays the increase of other contacts and adds
the amount of the proxy overload. We in this article, while using UDP, as the
Transport layer protocol, by regulating the Invite Retransmission Timer appropriately
(T1), have improved the SIP functionality. Therefore, by proposing an Adaptive
Timer of Invite message retransmission, we have tried to improve the time of
Session initiation and as a result, improving the performance. The performance
of the proposed SIP, by the SIPP software in a real network
environment has been implemented and evaluated and its accuracy and performance
has been demonstrated.