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How SIP Trunks Work

If you have been investigating different options for business telecoms, you have probably heard mentions of SIP Trunks. In this article we are going to give an overview of what SIP trunks are, why a business would use them and how Carden Telecoms can help set them up for you.

What is an SIP Trunk? 

SIP (Session Initiation Protocol) is a method for allowing you to make a voice over IP (VoIP) call. It is an application layer protocol for establishing a real-time connection between two endpoints (phones). 

SIP trunks are the digital equivalent of a phone line. An SIP provider can connect one or more channels to your PBX using SIP trunks. These trunks allow you to make local, long-distance, and international calls over the internet. SIP trunks can be connected to either an on premises or cloud-hosted PBX. If you have an your own on-premises PBX in your office, a telecoms provider can connect to it and allow you to make outbound calls using your existing phone system. 
 
Simply put, SIP is the technology that allows you to build, modify, and terminate sessions with one or more parties over an IP network. This means that you can make calls to and from your VoIP platform of choice to any other phone, including analogue phone lines, mobile phones, and other VoIP platform. 

What is an SIP Channel?

If you have been researching SIP trunk suppliers, you will have seen mentions of ‘channels’.  At any given time, each channel can handle one incoming and one outgoing call. As a result, the amount required by your organisation will differ. Small companies, such as a shop, may only need one or two channels, while call centres or the sales departments of large companies, may need 50 or more channels. 

When deciding on the number of channels to have installed, consider the seasonality of your company. Think of how many channels you would need on your busiest day. You should also make sure you are future proofing your telecoms, if you are planning to expand your business in the near future, you should ensure that you have the required number of SIP channels available to allow this. 

Assuming I Had Enough Channels, How Many Simultaneous Calls Could I Make Over SIP?
Your available bandwidth will be the ultimate cap on how many simultaneous calls you can make. Each non-compressed call consumes between 85-100 kbps. Most internet connections, whether home or business, will have a slower upload speed than download speed. As calls over SIP involve receiving and sending data, you should use your upload speed to determine how many calls you can make. 

If you are struggling to estimate how many calls you could make, how many channels you would need, and whether you would also need to upgrade your internet connection, Carden Telecoms team can help calculate this for you as part of a free consultation. 

How Can Carden Telecoms Help Supply SIP Trunks? 

Carden Telecoms can install SIP trunks for you.  This can be done as a stand-alone operation, but it’s usually included in one of our business telecoms bundles that includes VoIP, broadband, WiFi, and phone lines, among other things. We can also build a bespoke telecoms package to precisely suit your business’s needs.

There are other advantages to contacting a third-party business telecoms provider like Carden Telecoms, rather than installing the SIP trunks yourself. Carden Telecoms can assist you in determining how many trunks or channels the company needs, as well as professionally installing them, configuring them, and ensuring that the whole installation is recorded and carried out in compliance with relevant data privacy regulations. 

Any physical handsets which are required can be configured for VoIP at our offices and delivered to your premises – all you have to do is plug them in. Or our engineers can attend your site in person and install them for you. 

After the installation is complete, a SIP customer portal can be used to manage and customise your SIP trunks from a single web-based interface. Carden Telecoms also have dedicated support staff available that will be able to help you if you have any queries. 

We hope this has been a useful guide to what SIP trunks are, how they work, and how Carden Telecoms makes the process of installing, configuring, and managing them easier. If you would like to earn more about SIP Trunks, or any other aspect of business telecoms and how it could help your business, speak to our team today.

Author: Dave King

Dave King is the Co-Founder and Director of Carden Telecoms and the wider Carden IT Group. Dave is experienced in business telecoms with a focus on cloud telephony and connectivity services.