Why SIP Will Win

By now most of us in the telecommunications industry have heard all about the virtues of SIP from a wide variety of sources. The buzz has been going on for a number of years and has now reached a point that the discussion has evolved from a futuristic view reminiscent of science fiction to business-level applications that are being used in a variety of business applications today. SIP support is finding its way into communications servers (IP PBXs), IP client devices, gateways, applications, and firewalls. In fact, you might be using SIP every day and not even realize it. So, how will SIP (define - news -alerts) impact converged enterprises and how is its adoption likely to change the telecommunications landscape.

If you look back at early Enterprise IP Telephony reports before 2000, they claimed that we would all have thrown out our PBX systems and replaced them with IP PBXs by now. But that process has occurred at about half the rate that was initially expected. Why is that? At least partially to blame was the H.323 standard (really a recommendation) that these systems were built on because it was defined broadly, such that virtually all vendors products met the standard. Unfortunately, H.323 was not defined narrowly enough to ensure interoperability. As several more versions of H.323 came out over time to address the issues, the Internet generation grew hungrier for their Internet and wanted more than traditional telephony over IP, they wanted SIP. The Session Initiation Protocol developed by the IETF (Internet Engineering Task Force the folks who brought us Internet standards) was built on Internet standards like HTTP (Hyper Text Transfer Protocol commonly used for Internet Web pages) and SMTP (Simple Mail Transfer Protocol for Internet messaging) so, right away it was compatible with the Internet and supported a number of forms of communication such as voice, video, text, and chat.

While the H.323 systems added mobility and the ability to distribute IP Telephony systems across a LAN, MAN, and WAN, they basically delivered a similar feature set to traditional systems. SIP is bringing a whole new load of very compelling features such as instant messaging, single click video conferencing, chat rooms, Presence (the ability to share real-time status information between group members), collaboration, as well as an intelligent single number follow-me solution based on the device the user is logged in to just to name a few. And features will continue to evolve quite quickly and easily since the end devices will have the intelligence. In other words, the network in the middle doesnt have to do much more than provide reliable connectivity. Relatively dumb and relatively smart endpoints will communicate by negotiating for the lowest common denominator of simple services. Or at the other end of the spectrum, groups of smart endpoints can have multiple streams of video, images, multi-channel music, audio, text, chat with full security between individuals or large groups.

Regarding cost savings, part of the benefit has been in being past the learning curve and having true factual cost data to work with. Where costs were often higher than expected initially, prices per port for IP phones (dont buy one that cant support SIP) have dropped and quality has risen as with anything that can be mass produced. With the advent of low-cost standard USB headsets and Web cams to take advantage of SIP applications it is inexpensive, easy to use, and people love it. Consider how expensive and complicated ISDN video used to be. Now a person with a SIP client can make a voice call, a video call, or both in a matter of seconds over their IP network without any special configuring or multiple networks to support. In fact, if that user wants to add participants and have a multipoint videoconference they simply invite others by selecting them with their mouse.

The ubiquitous Internet in combination with VPN and SSL security allows SIP-equipped mobile workers to work from virtually any hotel, airport, or home offices wired or wireless connection. Productivity levels increase as they take all of their communications capabilities with them wherever they go.