what is sip

Do you want to make a simple change to your business that can save you money and simplify your work day? Not only does SIP trunking provide these benefits, but it’s also a flexible system that’s able to grow with you.

So what is SIP? Read on to learn exactly what it is and how it can benefit your small or medium-sized business!

What is SIP?

Simply put, SIP trunking allows you to make calls using an internet connection instead of a traditional phone line.

SIP stands for Session Initiation Protocol. Offered by a service provider, it’s a technology that provisions voice over IP (VoIP) connectivity to transfer digital packets of voice, data, video, and more at the same time. You can think of a SIP session as a regular VoIP call between two people, or a multi-party conference call.

In contrast, before SIP most telephone calls were carried by the Public Switched Telephone Network (PSTN). The PSTN is made up of a network of copper phone lines on a circuit-switched network, which requires a physical connection between two points to make a call.

SIP trunking provides the same service you would get from a traditional, analog phone line of copper wires connecting two points. However, it acts more like a virtual phone line, using your cable modem, DSL, ethernet, etc. to connect your phone system to the network.

SIP Channels

SIP channels are supported by each SIP trunk. You would call a single incoming or outgoing call a SIP channel.

No matter how many concurrent calls your business expects, a SIP trunk can hold an unlimited amount of channels, so only one SIP trunk is necessary.


You might hear the terms SIP and VoIP being used interchangeably, but they aren’t the same. VoIP is an umbrella term that refers to any phone call that’s made over the internet. SIP is a specific technology that enables VoIP.

Benefits of SIP Trunking

The SIP “trunk” is installed onto your internet connection, eliminating the need for traditional phone lines. This means that no additional hardware needs to be added, even as your business adds or removes lines, drastically reducing charges.

Lower Cost

Not only does less hardware reduce charges, but VoIP, in general, has a lower price structure than traditional phone services. Depending on the type and quantity of calls your business receives, you can save up to 50% on your monthly bill. Oftentimes, unlimited local and long-distance calls to most of North America will be bundled into your monthly fee.

If you’re a small business, you won’t need to pay for services you don’t need. SIP providers offer scalable services that can allow you to purchase a single channel at a time, and other upgrades such as call recording, usage reporting, or virtual voicemail can be purchased later.

Ease of Use

Another reduction to cost is the simplicity of its installation and maintenance; it doesn’t require an in-house IT staff to keep things working. You won’t need to scramble to find an IT professional or a telecommunications expert to troubleshoot issues, meaning less downtime when hiccups arise.

However, any hiccups or issues that may occur with your phone line usually won’t be an inconvenience. This is because call lines can be quickly diverted without effecting your business in any way.

Improved Sound Quality

Advances in technology have improved VoIP sound quality, to the point that calls can be crystal clear. As long as you have enough available bandwidth, you can enjoy HD quality voice and clearer audio with this kind of call system.

You won’t have to worry about static, loss of service, or dropped calls because of its larger frequency range. Why should you care about sound quality? Simply put, it’s better for customer service. There’s less frustration between you and your clients when information is transferred clearly and consistently.


SIP trunking gives you a large amount of flexibility. You can take your work calls from any location as long as you’re connected to the internet, as your phone calls can be automatically forwarded to your mobile device. You no longer need to linger near the phone in your office if you’re expecting an important call!

Not Location Bound

Since SIP trunks aren’t bound by location, you can easily change locations without having to change your marketing material and inform customers. You also won’t have to pay to forward calls to your new office. If you’re a startup or a small business that’s expecting growth, this flexibility eliminates future headaches.

Extra Services

Depending on the provider, many additional services can be included or offered at an additional cost, such as:

  • Routing of calls to 911 services with caller location information
  • Interconnection with cellular networks – a call placed to a cellphone will also ring on a desktop phone
  • Protection against toll fraud
  • Protection against denial-of-service (DoS) attacks
  • Virtual inbound phone numbers
  • Usage and performance reporting
  • Ability to route calls to multiple locations based on different policies

Things to Consider

Since SIP trunking uses an internet connection rather than physical lines, you’ll need to consider your bandwidth and your business’s requirements when it comes to call volume. If you don’t have sufficient bandwidth, this can also affect the call quality. However, it’s a simple fix that just requires a call or email to your service provider.

How to Use SIP Trunking

SIP trunking is a far simpler service than traditional phone lines, so you won’t have to keep multiple manuals floating around the office! Here are some things to consider when you’re about to install your SIP trunk, along with things of note you can plan out ahead.


It’s important that you ensure your internet service has enough bandwidth to support your calls. However, most broadband internet connections today are fast, to the point that dozens of calls can traverse your data connection without any issues.

QoS (Quality of Service)

Quality of Service prioritizes traffic on your network and is typically preconfigured in your router settings. You want to ensure that QoS is properly configured so that it can prioritize and properly transmit your VoIP phone calls.

For instance, if QoS isn’t properly configured and you’re downloading a large file, if a VoIP call was initiated at the same time, the audio quality would probably be downgraded. This is because the voice packets of data are being lumped in along with the packets of download instead of prioritized first.


Before you activate your system, it’s important to plan out your call routing, or setting up where you want calls to go. Although you can change this later, it’s simpler to get the foundations right first and so your customers can be properly routed to the right departments.

Configuring directory numbers is also something you can do in advance, which is an easy way to provide customers with a fast and easy route to talk with who they want.

One of the great advantages over traditional landlines is the ability to call a client through the click of a mouse instead of punching in numbers.

Upgrading Your System

By now you shoulder understand exactly what is SIP, and the benefits of SIP trunking. Taking into account its flexibility, ease of use, and cost, it’s easy to consider it an upgrade compared to traditional phone lines.

Besides its benefits for you, SIP trunking is also beneficial for your clients. They don’t have to struggle without date directories, inaccurate call routing, poor sound quality, or dropped calls. Believe it or not but some people still prefer phone calls, and if you’re delivering consistent quality, this is huge for your brand trust.

SIP trunking is all about creating a more flexible phone system that works with your business and its growing pains rather than against it!

Ready to get started with SIP trunking? Fill out this form to create a free SIP trunk account today!

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