Session Initiation Protocol (SIP) is a signaling protocol developed by SIP working group specified by the Internet Engineering Task Force (IETF), SIP is a text-based protocol similar to SMTP and HTTP, used to create, manage and terminate sessions on IP data network at application layer. A session could be a simple two-way telephone call or it could be a collaborative multi-media conference session. Such sessions include peer-to-peer voice, video, chat, interactive games, and virtual reality. This makes possible to implement services like voice-enriched e-commerce, web page click-to-dial or Instant Messaging with buddy lists on IP based data network resulting in reduced costs, improved customer service and easily manageable communications architecture. SIP is designed to address the functions of signaling and session management within a packet based telephony network. Signaling allows call information to be carried across the network boundaries. Session management provides the ability to control the attributes of an end-to-end call. In recent years, SIP has been the choice for services related to Voice over IP (VoIP). It is a standard (RFC 3261) proposed by Internet Engineering Task Force (IETF). SIP is still growing and being modified to take into an account all relevant features as the technology expands and evolves.

SIP , IETF , SMTP, Text-Based Protocol

[1] J. rosenberg, h. schulzrinne, g. camarillo, a.johnston, j. peterson, r. sparks, m. handley, and e.schooler, sip: session initiation protocol," rfc 3261(proposed standard), jun. 2002, updated by rfcs 3265, 3853,4320, 4916. [online]. available:
http://www.ietf.org/rfc/rfc3261.txt
[2] Handley, m., v. jacobson, �sdp: session description protocol,� rfc 2327, april 1998.
[3] Schulzrinne, h., s. casner, r. frederick, and v. jacobson, �rtp: a transport protocol for real-time applications,� rfc 3550, july 2003.
[4] S. lanzisera, b. nordman, and r. brown, �data network equipment energy use and savings potential in buildings,� energy efficiency, vol. 5, pp. 149-162, 2012, 10.1007/s12053-011-9136-4.
[5] N. freed and n. borenstein, multipurpose internet mail extensions (mime) part one: format of internet message bodies," rfc 2045 (proposed standard), united states, 1996. [online]. available: http://www.ietf.org/rfc/rfc2045.txt.
[6] J. elwell, connected identity in the session initiation protocol (sip)," united states, 2007. [online]. available:
http://www.ietf.org/rfc/rfc4916.txt
[7] Stream control transmission protocol support in session initiation protocol proxy server by thomas kwok cheong pang b.a.sc. (computer engineering), simon fraser university, 1995.
[8] session initiation protocol , kk tan and hl goh. p.13101314 volume 2, ieee international conference on information technology, 11:th14:th of december 2002:
[9] in-stat - voip penetration forecast to reach 79% of us businesses by 2013
[10] S. baset, j. reich, j. janak, p. kasparek, v. misra, d. rubenstein, and h. schulzrinnne, �how green is ip-telephony?� in proceedings of the first acm sigcomm workshop on green networking, 2010, p. 7784.
[11] Walsh, steffan fries, national institute of standards and technologies. nist special publication 80058. january 2005, p. 3945.
[12] Design and implementation of a sipbased voip architecture , s. zeadally and f. siddiquini ieee aina 2004 sip, session initiation protocol used in voipkarin tybring,petra wahlund, zhu yunyun