4 Reasons to Use SIP Trunks

How to Buy

As more businesses seek to lower their costs while gaining the collaboration benefits of unified communications, they are moving to SIP trunks to connect their business phone systems to the outside world. Traditionally, T-1 and ISDN Primary Rate Interface (PRI) circuits have been used for trunking, but the popularity of SIP trunks is growing as the service becomes more widely available. In fact, according to Infonetics’ market survey, 38 percent of companies are using SIP trunking today, and that number will grow to 58 percent in 2015. 

“SIP is a protocol designed to be used in the Internet age that is very flexible,” said Rich Winslow, ShoreTel’s manager of sales engineering. “It supports multiple levels of communications and is the underpinning of UC.”

Get Your SIP Trunks On

Here are four reasons to consider using SIP trunking the next time your communications service contract is ready for renewal. 

  1. Maximize flexibility and capacity. Using SIP trunks allows you to run voice, video and data traffic over the same IP network connection, and that enables you to consolidate WAN connections and make the most of the bandwidth you are buying. SIP gives you greater flexibility in other ways too. With traditional circuits, you have to buy in blocks of 23 trunks in North America (or blocks of 30 in Europe). If you only need 26 trunks, you will need to pay for 46. But with SIP, you pay for the number of trunks that you actually need. Plus, many of the SIP trunking services support busting, so you can pay-as-you-go if your traffic suddenly spikes, so SIP proves to be more flexible to changing demands. 
  2. Reduce communications costs. Organizations that adopted SIP trunking saved an average of 33 percent a year on telecom costs, according to a 2012 Webtorials SIP Trunking State of the Market Report. In addition, moving to an IP PBX can enable you to reduce long distance costs through least-cost routing. 
  3. Enable collaboration services. More than a cost savings, SIP is an enabler of collaboration services by extending voice and video between your organization and the service provider’s network. Using SIP positions your organization to use the full suite of unified communications, including videoconferencing, collaboration and presence. 
  4. Consolidate network connections. SIP can make it easier to interconnect data centers. And you can eliminate many of the separate analog and TDM trunks that are servicing your company’s headquarters and branch offices. You can use SIP trunks at your head office or data center to service all of your branches around the country or world. This makes it simpler to route calls if you operate a call center or have a follow-the-sun workflow. Alternatively, each branch office can have its own SIP trunk connection, which may provide greater resiliency and reduce traffic across the wide-area network. 

4 Considerations Before You SIP

Here are four considerations before you begin using SIP trunking at your organization. 

  1. Take security seriously. With SIP, your phone system is basically connected to the Internet. It is essential to use a SIP-aware firewall or session border controller (SBC) to protect the connection between your company’s network and the service provider’s network. Without a firewall or SBC, your network has greater exposure to distributed denial-of-service attacks, service thefts and fraud. These solutions hide your internal network and users’ IP addresses from the outside world as well as monitor the traffic in and out to block improper communications. Learn more about SIP trunks and UC system security. 
  2. Interoperability can be a challenge. Different vendors and service providers have implemented SIP a little differently, and these different flavors can cause interoperability speed bumps. The industry is making progress on interoperability through efforts like the SIP Forum’s SIPconnect, but still you should pay careful attention to interoperability and test thoroughly. When choosing a SIP service provider, also verify that the service is certified to work with your IP PBX. 
  3. Limited geographic availability. SIP trunking services are more widely available than ever, but they may not be available everywhere you have locations. 
  4. Support for fax. Different SIP trunk providers may use different methods for handling fax, and others may not support fax at all. Be sure to inquire as you select your SIP trunking provider. 

ShoreTel’s SIP Support

ShoreTel is no stranger to SIP, and first introduced SIP-supported offerings in 2005. SIP is the underpinning of ShoreTel’s Unified Communications solutions and has enhanced its offerings as the standard has evolved and more ITSPs (Internet telephony service providers) began offering the service.

ShoreTel has an established program for SIP certification within our Innovation Network, with more than 30 partners participating, both large and small providers, including AT&T, CenturyLink, TelePacific, Time Warner Telecom, Verizon, Windstream and XO Communications.