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A Step By Step Guide To Setting Up An SIP trunk?

alinajoris profile image Alina Joris ・3 min read

An SIP trunk is a virtualised phone line which replaces the need for physical/analogue phone lines, they connect your existing PBX system to the wider internet allowing you to make and receive calls via IP.
In this guide, we’ll give you step by step instructions on how to install and set up your own SIP trunk. If you do not have the time or technical skill to complete this yourself, consider contracting the services of an enterprise telecoms provider.

How to set up a SIP trunk
It is possible to set up a SIP trunk on your own, although it may be a bit of a challenge. In order to do it correctly, you will need to have a good understanding of IT networking and some rudimentary coding skills. It should be easy enough if you have worked in the development of IT or software.
In order to set up an SIP Trunk, you will need:
• A computer with an internet connection
• Details on your PBX, your SIP trunk and the account details for your existing VoIP phone system
• Your static IP address
Follow these steps:

  1. Access your PBX system’s dashboard.
  2. You should see an option for ‘Trunks'. Select it.
  3. Add a new SIP Trunk and give it a name
  4. Assign an outbound caller ID (this will normally be your business phone number). 5.Set your maximum number of channels. 6.Complete the SIP peer details.
  5. Register the SIP Trunk – if you use an external VoIP provider, you may need to register directly with them (this is known as a ‘register string').
  6. Save your changes and apply your new configuration. Your SIP Trunk should now be connected and live. If all has worked correctly, you should be able to make & receive calls through your PBX.

What does SIP peer details refer to?
The SIP peer details refer to the system governing how your SIP trunk and your IP system communicate. This exists as a section of code. You can write this code from scratch yourself or use existing code snippets if they suit your requirements.
Depending on your level of coding skill and the level of functionality which your business requires, you can set specific rules and exceptions for how the systems connect.

Should I set up the SIP trunk myself?
Before you install your SIP trunk, it is worth considering the following questions. Depending on the answers, it may be best to have an expert contractor or business telecoms provider install on for you.

How are your IT and coding skills?
If you are skilled in IT, with a good knowledge of both coding and IT networking, installing and configuring an SIP trunk should be within your ability. Follow the steps listed in this article.
Using a professional will cost more but is likely to be a more secure and reliable long-term solution unless you are supremely confident about doing it yourself.

When do you need your SIP trunk?
The urgency with which you need to have your SIP Trunk operational should play a role in deciding whether or not to bring in outside help as should how much available time you have to spend on the task.

If you have the time to learn and experiment by doing it yourself then that may be the best option. However, if time is of the essence, you should contact an external IT and telecoms expert and explain to them how you would like your SIP trunk setup.

What is your budget?
How much budget you have available to spend on your telecoms as a whole and on SIP specifically is an important consideration to make. If you install and configure an SIP yourself it is technically “free”. However, if you do it incorrectly, its malfunctions could cost you money in the long run through lost earnings and you may have to pay to get a professional to fix it for you in the end anyway (which will also cost money).

What is the purpose of the SIP trunk?
You should consider the reasons you need an SIP trunk. The needs of a business with 1 or 2 SIP Trunks (like a start-up) will be different to those of a corporation with an inhouse call centre who may need dozens or even hundreds of SIP trunks.
The best method of installation will therefore depend on your reasons for needing SIP trunking, you may be specifically looking to cut your overall call costs, to update your phone system and add more features, or help unify your communications across your organisation. Many of these goals can be more easily reached with the assistance of a third-party enterprise telecom provider.

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