What is SIP?

Our telecom industry just loves acronyms, which roll off our tongues in steady streams as though a different language is being spoken. Take “SIP” for example. SIP has been around for over a decade, but the term is still an enigma among small business managers, despite the fact that SIP and other modes of business VoIP are approaching mass market adoption. Perhaps the main cause of the confusion is the fact that SIP is often given other names within the industry or maybe because it’s represented in unintelligible “techie” terms. Hopefully we can briefly clarify the meaning and application of SIP and answer some of the most commonly asked questions.

Session Initiation Protocol (SIP) is the signaling format of Voice Over the Internet Protocol (VoIP). SIP and VoIP are terms that are often used interchangeably, even though VoIP technically has a much broader application. SIP is a proven method for using an Internet connection for the purpose of voice transmission. The virtual paths over which SIP calls travel are most commonly called “SIP trunks” and “call paths.” They’re also less formally referred to as “VoIP phone lines” or just “Internet phone lines.” In the final analysis, they are economical alternatives to office phone lines and no more complicated to use than POTS…oh, that’s another telecom acronym that stands for “plain old telephone service.”

You don’t need to have an IP phone system to install SIP. If you do have an IP PBX with a VoIP-ready interface, you’re ready to go. If not, you can keep your existing phone system and still use SIP, in which case, you would need a network device that converts the phone signal to IP. These network devices vary in price, depending upon the number of required trunks, QOS and network security, but they are usually much less expensive than the typical PRI cards and other premise equipment used with a traditional PBX. If you’re in the market for a new IP phone system, you can purchase one from Cisco, Avaya or Shoretel, or you might alternatively choose a “hosted” VoIP PBX solution like our InfoTalk Pro, which is offered as a managed service.

With InfoStructure’s SIP, you don’t need to obtain new phone numbers when converting from a non-VoIP application. Your existing phone numbers can be “ported” by most SIP carriers. You can also order new numbers local to your area or “virtual numbers” – phone numbers with area codes and exchanges outside of your local area, whatever works best for your business. In addition, you receive one free phone number (DID) per SIP trunk. If you require more numbers, they’re available at only $1.00 each per month. Also included are caller ID with name, call hunt groups, and call detail reports via web portal.

A commonly asked question is regarding the size and type of Internet connection needed to accommodate SIP. A reliable Internet broadband connection is a prerequisite for any VoIP service, regardless of whether it’s DSL, wireless, Ethernet over copper, or fiber optics. The amount of bandwidth is definitely a consideration, and it depends upon your unique business needs for both voice and data. The bandwidth per SIP trunk varies with the type of compression used in the SIP carrier network, but as a rule of thumb with our SIP, you can conservatively estimate 80 Kbs per call, including overhead. So eight concurrent calls, for example, will use up to 640 Kbs of bandwidth.

The time that it takes to install SIP depends mainly upon what is needed to fulfill your specific requirements. A simple installation can take only a couple of days after your order is placed. A larger, more complex installation requiring multiple locations and network equipment installations could take up to two weeks or longer.

We hope this helps to remove some of the mystery surrounding SIP! For information on SIP pricing, check out our SIP product, InfoTalk Plus, available in special rate plans with both unlimited and metered usage. If you have any questions, please call us. Our Oregon call center is open 7 X 24 every day of the year with friendly and knowledgeable service reps waiting to take your calls and answer your questions.