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Making the Most of SIP Trunks

What Are SIP Trunks?

SIP stands for Session Initiation Protocol and, put simply, allows users to easily make and receive voice and/or video calls over the internet. Trunking is the manner in which multiple lines can be connected to the same network and is at the core of any large-scale telephone system. SIP trunking enables the creation, modification, and termination of calls for any number of concurrent users. SIP Trunking is a form of VoIP (Voice over Internet Protocol) which is designed to plug directly into a company’s IP-enabled PBX (Private Branch Exchange).

SIP Trunks are designed to replace the now-outdated copper lines of the traditional PSTN (Public Switched Telephone Network). Whereas the analog PSTN is a circuit-switched network, requiring a physical connection between each point, SIP Trunks are entirely digital. This means that two – or more – users can be instantly connected, from anywhere, to anyone in the world as long as they have a phone number.

By using SIP trunks, an organization can connect any number of concurrent users to their existing PBX system allowing for unlimited local, long distance, or even international calls.

How Do SIP Trunks Work?

In short, SIP Trunks function as the access point between a phone network and the Internet Service Provider. Historically, phone systems required physical, copper wiring to connect each and every phone line to a central point. Using SIP Trunks, however, allows for any phone to connect to any other – using existing data networks. Put simply, SIP Trunks replace outdated physical networks with modern digital ones. As such, all that is required to switch over to SIP Trunking are an Internet connection, an IP PBX (Though older models can be adapted quite easily), and VoIP adapters or network connected phones.

What Can SIP Trunks Do For You?

The benefits of incorporating SIP Trunks into your network are easy to see; from lowered costs to increased access we’ve outlined exactly what you can expect SIP Trunks to contribute to your enterprise below:

  • Immediate Savings
      • Even small businesses can save from 40%, [all the way up to 90%](, by switching to SIP Trunks from traditional landline systems.
  • Freedom and Mobility
      • With conventional PRI systems, it is necessary that every unit be physically connected. This severely restricts options for office space and remote workers. SIP Trunks are limited only by the available bandwidth.
  • High-Quality Audio/Video
      • Using Tier-1 networks, users on all ends of a call are guaranteed a high-quality, lag-free experience.
  • Low Up-Front Costs
      • SIP Trunks connect directly to any IP enabled PBX, even older devices can easily be adapted to fit the new technology. Aside from the initial setup fees, there is no new hardware required for most systems.
  • Limitless Growth Potential
    • Unlike traditional PRI Systems, adding new lines to, or removing old ones from, a SIP Trunk can be done nearly instantly and with no additional installation or work required.

How Much Does It Cost To Set Up A SIP Trunk?

Initial costs of setting up a SIP Trunk vary based on each organization’s specific needs, however, most users can expect to pay an initial set-up fee of anywhere from $0 up to $150 with monthly costs typically ranging from $25-$50 per month per Trunk. Most SIP Trunk providers will offer plans with unlimited calls (both in-bound and out-bound) to local and long-distance numbers as well as greatly reduced rates on international calls.

Calls, however, are limited by the number of channels available; with each channel capable of handling one call at a time. Should all channels be engaged, no new calls can be made in or out. But, thanks to the decentralized nature of SIP Trunking, new channels can always be easily added, allowing for highly custom scalability

How Many Calls Can SIP Trunks Handle?

Like anything else, calls over SIP Trunks are limited by the available bandwidth. However, the required bandwidth per call is quite low.  For example, a network with an upload speed of 10 Mb/s would be comfortably able to handle up to 100 calls at a time.

SIP and VoIP

While SIP and VoIP are often used interchangeably, it is important to note that they are not the same thing.  VoIP (Voice over Internet Protocol) is a blanket term referring to any service which sends voice calls through the internet (Skype, Discord, WhatsApp, etc.), whereas SIP is a specialized protocol for handling large call volumes to/from a single network.
Read more on the differences between SIP and VoIP.

Crystal Clear Audio Quality From Anywhere

Thanks to recent advances in audio processing technology the quality of calls made over the Internet is now indistinguishable from those made over conventional landlines.  By utilizing Tier-1 carriers to connect directly to the main artery of the Internet providing the highest quality and priority for your calls. Additionally, thanks to a variety of available audio codecs it is possible to adjust your preferences for either the highest, uncompressed audio, or a more compressed audio which allows for a greater number of concurrent calls.