Product hero

What is SIP Trunking?

SIP trunking is a way to deliver telecommunication voice and media services over the Internet. If you currently have a VoIP phone system or PBX (Private Branch Exchange) that supports SIP (Session Initiation Protocol), then SIP trunking can be a means of delivering high quality, reliable digital voice services for your business without the cost of additional hardware or the need to switch phone systems.

In order to understand SIP, you must first understand VoIP, which is an acronym for Voice Over Internet Protocol. VoIP enables you to get phone service through the Internet versus getting it from your local phone company. VoIP provides a means of turning analog phone signals into digital signals that can be sent over the Internet. Since many companies already use VoIP within their PBX on the Local Area Network (LAN) to connect to IP phones, SIP makes use of VoIP to take advantage of shared lines.

There are many benefits associated with SIP trunking, but two of the biggest are the cost savings and flexibility it offers to support business growth. Read on to learn how a SIP phone system works and the value it can bring to your VoIP phone system or PBX as well as to your organization.


SIP Trunking 101

When your business grows, you’ll likely need to add phone lines. If your current phone system or PBX uses analog technology, that means one phone number per line – a costly option in terms of dollars spent, physical space needed and installation time required.

While digital lines offer a better alternative (1 wire/T1 = 24 channels), a T1 line is expensive. Plus, you still need the physical space and time for your local phone company to install it. And while T1s can handle more capacity than an analog line and provide better quality over long distances, once you reach that capacity, you have to install another T1. So once again, cost and the ability to scale quickly become issues.

So what’s a business to do? Enter SIP trunking. It speaks directly to a business’ need to keep costs down while quickly scaling to meet demand.

With SIP trunking, a call is routed through your current VoIP phone system or PBX using signaling information so your VoIP phone system or PBX knows where to send it. There is nothing additional to configure at your end, provided you have the aforementioned connection to the Internet and SIP-compatible VoIP phone system or PBX.


How SIP Trunking Adds Value

A SIP phone system is a great way to gain cloud benefits while maintaining control over your on-premise PBX solution. It blends the best of both worlds to reduce costs and support future growth.


  1. Improved Business Continuity

    On-premises solutions require a direct connection. If something happens to that connection, your system goes down. With SIP trunking, your VoIP phone system or PBX gains built-in redundancy with access to multiple carriers so if an outage does occur, your call quality and uptime won’t be impacted. Top SIP providers invest a lot into their network to ensure automatic failovers if a hardware or carrier issue should arise.

  2. On-Demand Scalability

    When your business grows, you need to add phone lines. If your current VoIP phone system or PBX uses analog technology, that means one phone number per line. As your business grows, you’ll have to forecast adding new lines in advance to prevent capacity issues, plus invest a lot of time and money into physical space and installation management required to turn up additional lines. Assuming you have a VoIP phone system or PBX that supports SIP, you can easily grow with your business without incurring extra costs. Call capacity can be increased on-demand to support unlimited concurrent calls, while ensuring you never pay for more than you need.

  3. Pair with Unified Communications (UC) Solutions

    A SIP phone system isn’t just compatible with your IP PBX or VoIP phone system – it can also be leveraged with other communications solutions such as UC. SIP trunking plays nicely with a variety of on-premises and cloud solutions to deliver a seamless experience that can work with your current VoIP phone systems or phone systems you may be considering for the future.

  4. Easy Implementation & Management

    A new SIP phone solution can be deployed within 30-60 days – or even a few weeks depending on the scope of the project. Because SIP trunking installation is handled behind the scenes primarily by your SIP provider, you will be able to get up and running without any disruption to your business. After the initial installation, adding trunks is as a simple as contacting your vendor. Plus, if your SIP provider offers other communications solutions, you’ll have one point of contact for all your communication needs.


Additional Benefits of SIP Trunking

Businesses are embracing SIP trunking in ever-increasing numbers, with more organizations planning to adopt it over the next several years. Why is a SIP phone system so appealing? Initially, it was all about budget and flexibility. But SIP trunking offers other benefits as well – benefits that are becoming increasingly apparent to businesses whose success depends on keeping up with customers and market dynamics that demand increasing flexibility while minimizing cost.

Beyond the four value-added benefits of SIP trunking noted above, below are four more reasons why SIP phone systems are growing in popularity:


  1. Consolidation of Vendors.

    While SIP trunking reduces costs by both lowering call rates and reducing infrastructure needs, it also allows businesses to reduce the number of vendors they must deal with. Many SIP providers also provide other solutions such as PBX, unified communications and contact center offerings, providing a single source for all your communications needs.

  2. A Better User Experience.

    IT isn’t the only department to benefit from SIP trunking. Because employees can make and receive calls seamlessly between Internet-based telephony devices, they can easily communicate with other employees throughout the organization and receive the same experience and level of service no matter their location.

  3. Improved Productivity.

    A SIP phone system’s ease of use allows an organization to realize significant productivity benefits. With SIP trunking, your workforce can take full advantage of unified communications, improving collaboration and reducing time spent jumping through unnecessary telecommunications hoops. Plus, with the built-in redundancy and failover destinations, downtime due to disasters or other disruptions is eliminated.

  4. High Satisfaction Levels.

    A SIP phone system provides high levels of voice quality. In fact, 96% of the decision makers surveyed by SIP trunking review site Software Advice were satisfied with the quality of their calls, with 73% noting they were either “extremely” or “very” satisfied.

Ready to talk to sales? Contact us.