Session Initiation Protocol (SIP) is a signaling protocol used to control multimedia communication sessions, e.g., video and voice calls over IP. This protocol is used to create, modify and terminate unicast and multicast sessions. Modifications may include altering ports, introducing new media streams, or inviting additional participants. This can include video conferencing, file transfers, instant messaging, presence information and file transfers. SIP was designed in 1996 by Mark Handley and Henning Schulzrinne. The Internet Engineering Task Force (IEFT) working group designed the latest version of SIP, RFC 3261. SIP is a text-based protocol employing many similar elements to Hypertext Transfer Protocol (HTTP) and Simple Mail Transfer Protocol (SMTP). Like HTTP, SIP follows a request and response model, wherein a client request summons a given function on the server and one or more responses.


Sip Trunking

Latest Headlines

Latest Headlines

SIP trunking adoption set to rise to 62 percent by 2017, says Infonetics

As more businesses see their premises-based PBX systems come to the end of life, more North American businesses say they are increasingly using SIP for a part of their voice connectivity...

CenturyLink adds app providing mobile access to business UC tools

CenturyLink is tuning into the growing mobile nature of its business customers with its Business Communicator app, allowing customers to connect their VoIP users to their unified communications services from computers and devices.

CenturyLink ready to take on cable as Comcast, Charter emerge in SIP trunking segment

CenturyLink acknowledged that it is in a competitive battle with Comcast Business, Charter Communications and other cable operators in the SIP trunking segment of the business services market, as more enterprise customers ditch their TDM-based PRI lines and analog PBX's for IP-based hosted services.

CenturyLink sees cable as an emerging SIP trunking competitor

CenturyLink is aware that Comcast Business, Charter and other cable operators are going to be a bigger threat in the SIP trunking segment of the business services market as more businesses ditch their TDM-based PRI lines and analog PBXs for IP-based hosted services.

Session border controller, IMS core revenues jump 23 percent, says research firm

The session border controller market is seeing benefits from the increased adoption of SIP trunking and emerging wireless Voice over LTE (VoLTE) services. According to a new Dell'Oro Group report, SBC and IMS core revenues together rose nearly 23 percent year-over-year.

IHS: More service providers are carving out IMS, NFV path

IMS and network functions virtualization (NFV) may be the hottest buzzwords in the telecom industry today, but a new IHS report revealed that only 8 percent of service providers it surveyed currently run these technologies in their networks.

Alaska Communications, Quintillion purchase North Slope dark fiber network

Alaska Communications and Quintillion Holdings, a regional service provider, are purchasing a fiber network from ConocoPhillips that they say will enable them to target business service opportunities in the region's growing oil and gas industry.

SIP trunking helped enterprise session border controller market hit $271M in 2014

Businesses' ongoing adoption of SIP trunking continues to be a boom for enterprise session border controller (SBC) vendors, a market segment that saw worldwide revenue rise to $271 million in 2014, says Infonetics in a new report.

Comcast Business addresses SMB, enterprise IP voice needs with SIP trunking service

Comcast Business is taking a long pass with its SIP trunking service, announcing that the service is available across its entire service area, covering 39 states and 20 major U.S. markets.

Alaska Communications brings SIP trunking to SMBs, enterprises in Anchorage

Alaska Communications (ACS) is now offering SIP trunking services to Anchorage businesses, the latest in a series of moves it has made to enhance its wireline service focus.