Girish Dharmaraj 
Mae Emuslan has been at Toku for four years when she first started off as our NOC Engineer, and evolved into her present role as a Voice Engineer. As Toku turns four, she reflects on how the company’s diversity has helped her team achieve new highs.
You’d be forgiven for thinking that SIP trunking is old news.
It’s certainly old technology. SIP trunks came into being almost two decades ago, with the growth of voice over internet protocols (VoIP).
But it’s still relevant.
In fact, SIP trunking may be more relevant today than ever, even in the age of cloud communications.
Why?
Because there’s still a whole load of legacy technology out there, and it’s not going to go away anytime soon. Also, it turns out that SIP trunk providers still have some pretty enticing business benefits to offer…
What is SIP trunking?
Before we dive into the business benefits, let’s first get a basic idea of what SIP trunking is and how it affects business communications.
In simple terms, SIP trunking allows companies to receive and make telephone calls through the internet. It’s a modern alternative to an ISDN (Integrated Services Digital Network) for making phone calls.
To go into a bit more detail, the best way to describe SIP trunking is with an example.
Let’s imagine a business that has a call centre operation for customer support. To increase efficiency and improve business continuity the company wants to apply VoIP technology. The objective is to replace traditional telephone networks that use circuit switches, with internet or VPN-handled calls instead.
They decide to install a private-branch exchange (PBX) which allows internal routing of voice calls across the data network. In other words, incoming telephone calls are handled by the company’s data network and can be routed from one individual to another within the company.
SIP (Session Initiation Protocol) trunking is a system that links up the public-switched telephone network (PSTN) to a data network. In other words, it allows businesses to make and receive voice calls over the internet through the traditional networks operated by telephone providers.
SIP trunks enable this by creating a virtual phone number (known as a DID) that connects to your data network. This is the number that customers can ring to reach your contact centre.
SIP trunk advantages and benefits for business
Although it’s a relatively old technology (by modern standards), SIP trunks still offer many benefits for companies looking to enhance their communications.
1. Reduce cost
There are considerable cost savings to be had by switching to SIP trunking compared to using traditional telephone providers. A traditional phone service will have different charges for local, long distance, and international calls. SIP trunking, on the other hand, has simple, easy-to-understand pricing that’s usually billed per-user, rather than a flat fee that may be overpriced.
The fixed pricing offered by SIP providers means that you get predictable monthly bills, compared to the fluctuations of telephone services. Apparently, companies achieve a saving of around 50% per month by switching from telephony to SIP trunking, and this can be much higher for companies that make lots of international or long distance calls.
Installation costs are low too, making SIP trunks even more cost effective. In other words, for a small short term investment, businesses can yield a large ROI almost immediately by swapping to SIP trunking.
Also, with SIP trunks you are free to choose the exact number of channels you need, compared with ISDN where you are limited to a choice of either 15 or 30 lines, leading to extra, unused capacity and increased cost.
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2. Flexibility and scalability
SIP trunking is far more flexible and easily scalable than old-school telephony. You can grow your operations quickly and globally by combining your voice and data networks, into a single, centralised entity.
The rapid speed of SIP scalability enables you to quickly set up communications at new sites in any location and allows you to empower remote workers with all the tools they need. The number provisioning capability of SIP trunks makes it easy to add or remove phone numbers as needed.
3. Call quality
Just think of all the things that can go wrong with telephone calls. Phone lines down due to heavy wind, switchboard problems, poor quality connections… the list goes on. SIP trunking, on the other hand, is far more reliable and offers consistent high-quality sound.
Many SIP providers include a mobile-failover routing which means that your phones will still operate even if there’s a system or network failure as your calls can be rerouted to employee mobile devices.
To get the best call quality possible, you should choose a provider that doesn’t aggregate traffic and owns the connectivity infrastructure. This means you’ll be closer to the source and call quality will be optimal.
4. Improved security
As SIP trunks connects calls through the internet, if you have robust internet security measures in place, it can be safer than making calls through ISDN. Most SIP providers include a firewall and fraud alert services that integrate with your communication software.
As long as the SIP trunking is set up and configured correctly with all security measures in place, with software regularly updated, then communications handled through SIP are one of the safest and most secure options out there.
5. Enables unified communications
Unified communications refers to having all your communication tools running through one system and data network. The advantages of unified comms are increased productivity, greater consistency, more flexibility, and higher reliability.
SIP enables you to use video conferencing tools, instant messaging, voice calls, media messaging, etc. through one data network. This means you can combine communication tools with management and team collaboration tools such as Microsoft Teams, or other cloud-based productivity apps and resources.
6. Elimination of physical infrastructure and no hardware
If you want to expand and scale up business communications using a traditional telephony system, you need to install a lot of new hardware and infrastructure.
SIP trunking installation requires no new hardware and no phone lines or networks. In fact, you can remove all of your old phone infrastructure to free up space if you want. The lack of hardware also makes SIP ideal for setting up remote workers, removing the need to give them a mobile device, thus saving some more money.
With SIP trunking, your company can provide a phone line to an internal or remote employee by simply assigning a data connection to a handset. Employees who work off-site can also be integrated directly into your business network, which means they can be given an internal phone number and an internal extension for convenience.
Things to consider before switching to SIP
There are a few things to keep in mind if you’re considering moving from PSTN to SIP trunking.
Firstly, you need to validate your phone number portability. To avoid delays, your SIP provider must send porting information to your telephone provider and check the structure of the PBX for connectivity issues. All the porting information must be checked and correct, otherwise it may hold up the transition.
To make things easier, some companies move their voice communications to the cloud, using cloud-based software such as Microsoft Teams and a SIP trunk provider like Toku.
Another important stage of SIP migration is testing connectivity. Before moving phone numbers over in real time, virtual tests should be carried out to check that all the SIP interactions work correctly across the data network and that everything is configured to your needs.
Mae Emuslan 
V K Sanjeed 