SIP (Session Initiation Protocol) - The Key Role in VoIP

Session Initiation Protocol (SIP) is a signaling protocol for establishing sessions in an IP network. But if you are like most of us, that means nothing to you. In layman's terms, SIP is a method by which various computers can talk to one another so that they can complete voice calls. The protocol is increasingly being adopted as the standard means by which computers communicate to facilitate VoIP or Voice Over Internet Protocol. So you can imagine SIP as a common language for new generation operators to speak to connect calls. However, there are no operators there is only your computer (or other hardware) and that of the person you are speaking with. That brings this introduction to some of the many benefits of SIP communication.

The goal of SIP was to provide users with many of the functions and features they typically expect with making phone calls, such as familiar rings, hearing the ring back tone when a call is placed, and the process of dialing a number. SIP goes beyond this however, also implementing a number of advanced features. Despite its’ convenient interface that mirrors that of a typical telephone call, SIP is based on an internet protocol rather than that of the telephone industry. Because of this, SIP is able to work seamlessly alongside other internet based protocols. This has allowed the technology to uniquely establish a user location, meaning that you can tell the IP address or "location" from which a person is making a call, something vital for offering emergency services. It also allows for coordination amongst the various participants in deciding upon what call features will be supported, as well as providing the protocol for call management which allows for adding, dropping, or transferring call participants.

One of the most exceptional benefits of Session Initiation Protocol (SIP) is its application with Private Branch Exchange (PBX). A private branch exchange is a private telephone network used within an enterprise in which users share a certain number of outside lines for external telephone calls. This provides a significant cost savings to the company because it allows companies to quickly and easily make calls within their institution, as well as save by limiting the number of external phone lines that must be maintained. SIP can extend these cost savings dramatically by offering users free long distance calls worldwide. Once again, because SIP is internet based rather than running over traditional telephone lines, the cost of call transmission are as cheap as say sending an e-mail, that is to say, Free! While PBX is already an efficient use of office resources incorporating SIP into a PBX means taking such savings and capabilities to a new level. Incorporating SIP gives users’ access to free interoffice communications, long distance calls, as well as huge savings in setup and transaction costs. These transaction cost savings are due to the fact that SIP is based on internet protocol allowing for the ability to physically move phones without any need for rewiring or new setup costs. Because that the system is peer-to-peer rather than cog and wheel like hardwired telephony means that there is no complicated setup necessary, but rather users can simply plug the phone into any available broadband connection and without the need for any complicated hardware or software, calls are ready to be made and received.

This brings us to what is potentially the greatest savings that SIP provides. We all hate to have to pay $2.00 for making a simple local call from a hotel room. But for those of us that have had to pay exorbitant long-distance charges from hotels, the level of angst felt reaches new heights. Add to this the fact that often companies require conference calling for their employees, a service that hotels are all too happy to charge a high premium to provide. For companies that have a lot of their employees traveling or practicing in various locales, the overhead costs of making such calls can really put a damper on year end profits. SIP offers a solution to hotel bills, and for that matter all telephone bills whatsoever. Just as sending an e-mail is free whether you are sending that e-mail to a person across the street or around the world, so making a call using SIP from any locale to any other locale in the world is free. All that is needed is a broadband connection. And just as one can send an email from wherever the internet can be accessed, SIP users can make their free calls from the office, the home, or even (gasp) the hotel room. Not to mention the huge savings in regular long-distance charges, the simple fact that long distance and local calls can be made for free from hotel rooms (most of which offer complimentary broadband service) is an enormous long-term cost savings. But add to this the fact that conference calls are available at no additional cost, which can be explained by following the principle that sending an e-mail to many individuals at the same time is just as cheap as one to one communication. Altogether these savings mean that companies who have in the past been laden with high local and long distance phone bills will be able to have their employees keep in close communication no matter their location for free.

SIP goes beyond this, however. Because SIP uses peer-to-peer connections there are no extra costs for having hundreds or even thousands of employees making SIP calls whereas the management costs for such a system under traditional telephony would be astronomical. This is never the case with PBXs that utilize SIP in a peer to peer connection format, however, where structural costs do not increase as your business grows and your usage of the PBX increases.

Session Initiation Protocol (SIP) offers customers of traditional telephony fantastic cost savings, the flexibility to make free calls from anywhere in the world at any time, and the ability to expand a PBX system with no setup costs. Because there is no complicated hardware or software necessary to setup SIP in a PBX, implementing the technology is as simple as having access via broadband to the internet. Due to these benefits as well as innumerable others, expanded use of SIP in PBX and in a variety of other settings is simply a matter of expanded customer exposure to the possibilities of SIP.