What is SIP Trunking?

What is SIP trunking exactly, and why is it so important for businesses to understand its benefits?

You’ll be glad to know that it has nothing to do with an elephant’s appendage, and everything to do with lowering business costs and increasing flexibility and productivity.

For those that find geek speak about as much fun as translating a 10 page phone bill —- ‘SIP’ stands for Session Initiated Protocol and is really just another way to enjoy the benefits of VOIP.

What is SIP?

In the world of technology, there seem to be too many acronyms to keep track of. But the most important for your business right now is SIP. SIP, or Session Initiation Protocol, was created by the Internet Engineering Task Force (IETF). IETF created SIP as an open-signaling protocol standard.

SIP Acts to Simplify Communication

SIP can connect a range of communication devices, such as phones gateways, proxies, servers, soft-phones (on PCS, PDAs, etc.), Private Branch Exchange (PBX) systems, instant messaging, videoconferences, and collaboration systems. With SIP trunking, your phone system calls are ‘translated’ to VoIP so that they can run over the Internet.

Why should businesses consider SIP Trunking?

Keep Your Current Phone System and Enjoy the Benefits of VoIP

Before SIP, enterprise communications had separate structures of voice and data communication. This separation can cause a breakdown in enterprise communication as the system cannot balance out fluxes in voice and data communication. This old system cannot handle an increase in calls and customers receive busy signals, while the Internet may be completely underutilized.

By connecting a range of devices, whether it be voice, video, or text, SIP simplifies communication and makes businesses technologically competitive. For example, calls to the user’s mobile phone, direct office line, and even home phone can be sent directly to an assistant during certain times of the day. SIP trunking offers businesses the best of both worlds. Keep your current phone system, but still enjoy the benefits of using VoIP: driving down costs, increasing agility and providing reliable, quality phone service.

Cost Reduction

Before SIP, businesses used Time Division Multiplexing (TDM) carriers. They connected their PBX telephone network to one of these carriers and lost money – these carriers charged money even when the lines were idle or busy, incurring toll charges and expensive long distance charges. Now with VoIP and SIP, companies can integrate voice, video and data for a much lower cost. SIP trunks allow for voice and data to be transported over an IP connection. Cost is reduced with employing a single IP pipe for communication. 

Find a SIP trunk provider that charges around $24.95/mo. per trunk or “line”. Try Press8 Telecom for reliable, and affordable SIP trunks.

The number of SIP trunks depends on how many calls the user will receive. For instance, a customer contact center may require a SIP trunk per customer service agent, so that each one could receive simultaneous messages. However, a smaller branch could do well with a SIP trunk per five or six employees. Correct setup and a strong Internet connection will ensure maximum efficiency and quality without time delays or data loss.

Little or No Equipment to Maintain

The equipment that you will need for SIP trunking depends on your current system. If you have an older PBX system, then you may need a SIP-ISDN gateway. A newer system may not require this additional hardware. The gateway acts as a translator between SIP and ISDN of the SIP trunks and PBX system. 

Decreased Accounting and Admin Costs

Even with multiple locations bills can be consolidated with SIP. So can support, reducing the office stress level and leaving staff to focus on revenue generating activities versus haggling over bills.

Not Connected to One Geographical Location

In addition, SIP is not tied to a particular geographic location, which means it has number mobility and can be used wherever and whenever. SIP trunking can do this because it links the communication system to a public telephone network with the same connection as your data services.

More Choices for Local Numbers

Benefiting from all the advantages of VOIP, businesses can also wield the power of having local numbers anywhere they like, regardless of where they are based. For inbound marketing this can dramatically increase trust; boosting response rates and conversions. For outbound call centers and telemarketing businesses also frequently report improved results and more connects when using a local number rather than a toll free one. When was the last time you picked up an anonymous 800 call?

With SIP trunking you can actually keep your current PBX equipment (analog or IP equipment) and take advantage of the features mentioned above. Just hook up with a VoIP SIP Trunking provider and start enjoying the cost savings, expanded routing choices, and more.


The technological benefits and cost-effectiveness of SIP trunking can be invaluable to big enterprises, small businesses and individuals. SIP utilizes existing equipment, applications and communication devices to simplify and expedite communication. SIP can even prioritize messages automatically for users, eliminating the headaches of sifting through hundreds of incoming messages. In addition, it reduces the costs for communication by utilizing the Internet for Voice as well as Data.To remain competitive in a world that moves incredibly quickly, businesses need to stay ahead of the technological curve, SIP and SIP trunking can make this happen.

Back To

Request a Free Quote