Discover how our products can revolutionize the way you communicate and collaborate.


Explore our advanced voice solutions designed to optimize your communication workflows.

Diverse range of DID number solutions designed to enhance your communication capabilities.

Experience unparalleled communication efficiency with our advanced SIP Trunking Solutions.

Cutting-edge technology to proactively detect and neutralize spam flags on your DID Numbers.


Wherever your audience is, our platform ensures seamless messaging across diverse channels.

Build customer journeys by fostering interactive conversations, all within the framework of your app. 

Connect with your audience in a simple and effective way through our cutting-edge SMS platform. 


Harness the power of IDT as your chosen carrier while leveraging your platform’s advanced features and services.

Integrate Twilio with our robust carrier routing platform to achieve unparalleled Voice termination system.

Experience reliable and high-quality communication services while leveraging the advanced capabilities of Genesys. 

Integrate IDT with the collaborative strength of MS Teams, unlocking efficient and feature-rich communication. 

Experience the power of our carrier network seamlessly connected to Plivo through our cutting-edge BYOC solution. 


Experience the power of our online voice tools, designed to simplify communication management. 

Ensure the authenticity and integrity of outbound calls with our STIR/SHAKEN Verification Check tool. 

User-friendly tool to verify the reputation of your business number, ensuring that it remains trusted. 

Compare and gain insights into outbound call expenses, optimize budget, and make informed decisions. 

Easily estimate and compare the costs associated with different DID numbers providers. 

Compare inbound VoIP rates among top CPaaS providers and optimize your inbound call costs. 

Generate custom SMS templates. 


Empower yourself with the resources you need to thrive in the dynamic landscape of communication.

Articles covering a wide range of topics.

Get answers to common queries.

Find instructions to make the most of our products.

Discover telecom insights and trends.

Find definitions of popular telecom terms.

Explore how our solutions have helped businesses.

Latest telecom trends, innovations, and market insights.


A global telecom partner built to meet your needs. 

Discover the story behind our commitment to delivering innovative solutions to connect people and businesses worldwide. 

Learn about our robust network infrastructure that spans across the globe, ensuring reliable and secure connectivity. 

Got a question, feedback, or need assistance? Our dedicated team is here to help!

Find partners or sign up for partnership programs.

Learn / Blog

All You Need to Know about Sip Trunking for Voice Termination

|  4 min
In this article

SIP trunking is the latest buzz phrase to hit the world of telecoms, but exactly what is it and what does it do? Basically, a SIP trunk makes a direct connection between your premises and the PSTN network, using internet technology. It’s a technology that’s being used as a replacement for ISDN lines because it’s cheaper and easier to scale as the business expands. It’s related to voice over IP (VoIP) systems but is aimed at business users who need to seamlessly link their telephone systems to the wider network. It is therefore often used with existing PABX systems because it can offer a relatively seamless transition.

Cost savings on voice termination

Business innovations are often sold on the basis of cost savings and they don’t always deliver. The greatest advantage of SIP trunking is in the way that it can help to cut communication costs. Not only are rental costs for SIP trunks much lower than for traditional ISDN lines, but you can usually save on landline call costs – or even get them free – too. It is, of course, important to balance this against quality. In order to ensure call quality, you may have to switch to a more reliable internet connection, such as a leased line. Even so, the extra costs of doing this should be offset by the savings possible from switching your calls to SIP trunking.

In many cases, a SIP trunk system will be compatible with your existing PABX equipment. However, you do need to check as this is not always the case. Service providers will usually be able to offer a service that checks compatibility and ensures that everything will work together to provide a smooth transition.

Communication strategy

Many businesses are turning to unified communications strategies (UC) in order to bring together all of their business communication needs via a streamlined set of gateways and interfaces. This is another area where SIP trunking can help to deliver. Crucial to UC is allowing systems to share information about the status and availability of users and how they are connected. Using SIP can allow a business to control multiple numbers regardless as to which network they are on or what device they are connected to locally.

It also means that mobile apps can connect directly to the SIP, allowing them to access the business phone system, helping you to save on your overall business call costs and allowing mobiles to make calls that appear to come from your main business number. Of course, it works the other way too, incoming calls to the main business number can be diverted directly to an employee’s mobile, so that field workers need never be out of touch.

It also becomes much easier to handle communication for multiple sites. Previously this might have required an ISDN line and a PABX at each location. Using a SIP, the number of connections can be reduced along with their associated maintenance costs, resulting in significant savings on communication costs.

Scalability of the system comes into play here too. Extra trunks can be added as required with minimal lead time, so it’s easy to cope with peaks of seasonal demand or meet the demands of overall expansion of the business. Capacity can easily be reduced again at quieter periods too, so there’s no need to pay for services you only use occasionally.

If you’re considering changing location, perhaps relocating to larger premises, a SIP trunking system allows you to keep your existing number structure. It also means you can manipulate numbers, so that calls can go out on a number that is not located to the geographic location, making calls appear to be from local branch offices for example.

Security and resilience

There are often concerns about services that use the internet. But provided that it is implemented properly, the risk of fraud should be minimal. Indeed, a correctly configured SIP trunk should allow you to secure your own traffic with dedicated firewalls or firewalled routers.

Any disruption of services can lead to major costs for a business. Using SIP for your communications can be a major positive when it comes to disaster recovery planning. Thanks to SIP trunking, you can easily divert your lines to another location, should you need to move to temporary office space, for example, while retaining your numbers and your service capacity. Diverting calls can be almost instant, so you can easily cope with an outage at a particular site or a sudden spike in demand at one location.

Given all of these advantages, it’s not surprising that more and more companies are adopting SIP trunking for their communications. In the UK alone it’s estimated that more than half of companies are now using SIP trunking for their voice systems.

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *


Meet our wholesale voice routing

Fulfill all your voice calling needs with our category leading wholesale A-Z Voice Termination.
Try IDT Express for a $25 Credit

Get $25 Free Trial Credit

Get IDT Express articles in your inbox

The best source of information in the telecom industry. Join us.

    Most Popular

    |  7 min
    Introduction to Toll-Free Forwarding In today’s fast-paced business landscape where...
    |  7 min
    Introduction to Caller ID Reputation Caller ID reputation is a...
    |  6 min
    The European Union’s General Data Protection Regulation (GDPR) has permanently...