In recent years Session Initiation Protocol or SIP has become a widespread protocol of choice for multimedia applications. In particular SIP has become quite popular in voice applications. Most major PBX manufacturers now support IP endpoints and also support SIP trunks and extensions. The growing popularity of the open source PBX software Asterisk and its various derivatives (e.g.Asterisk Business Edition, AsteriskNow, Elastix, Trixbox, Switchbox etc.) has also fueled the development and implementation of SIP.
Of note is the growth of the SIP compliant hardware industry. Major manufacturers like Aastra, Grandstream, Polycom, and Snom produce SIP phones that are in common use. Even proprietary PBX manufacturers like Avaya, Nortel, and Cisco have their own flavors of SIP firmware available for their IP telephones.
With the advent of SIP trunking as well as SIP-based hosted IP PBX solutions, the cost of owning a small business phones system has also shifted. Using SIP trunking, some businesses are realizing significant savings on long distance costs. With hosted IP PBX solutions, businesses can subscribe to PBX features and use SIP compatible phones without the necessity of purchasing an on premise PBX system. Not only can you save on hardware costs, but you can also save on installation and maintenance.
Early adopters have found some quality issues with SIP trunking. Most of these issues are inherent in VoIP technology (e.g. echo, latency, jitter). Better quality is often found with providers who monitor the connections to their network. This means that you usually have to purchase your digital trunk connection directly from them. SIP providers that offer broadband agnostic services that travel over the public internet often have more quality issues.
As far as SIP-based PBX equipment goes, there are many flavors of the popular open source Asterisk movement. Some are free and others have licensing costs. There are also many hosted IP PBX service cropping up around the nation with great success. Some even use Asterisk based platforms.
If you’re trying to save money with IP, then look into SIP trunking, SIP telephones, SIP-based PBX’s, and even hosted IP PBX offerings. SIP may be the avenue for you.