SIP Trunks from Synextra.
Break Free From Legacy Phone Lines.

SIP is the natural successor to traditional ISDN lines. By utilising existing PBX setups, SIP trunks give you greater flexibility, lower your monthly costs and vastly improve your business continuity plans. It’s also quicker to install and deploy, meaning you can start saving your business money immediately.

Talk To A Cloud Enabler About Communication Solutions

Why should I upgrade to SIP trunks?

The mature, modern and flexible replacement for ageing ISDN circuits, SIP Trunks use an internet connection instead of a traditional phone line, to bring you lower call & OpEx costs – as well as the resiliency your business needs to grow your business.


Lower Call Rates

By delivering the service over an IP connection, rather than traditional phone lines, SIP delivers a more reliable, yet lower costing solution than ISDN. Save up to 50% on line rentals and up to 60% on call costs.

More Robust DR Plans

With telephony being the most common way businesses communicate with customers, your business needs a continuity plan to ensure your callers can always get through. Simply divert your main numbers to backup locations or even to mobile phones and keep your business talking 24/7/365.

Greater Flexibility

Is your business condensing multiple offices to one city, but still wants to retain its regional presence? Retain your local, geographic numbers, without having to pay the forwarding costs you would previously with ISDN.
Cheap business calls through SiP trunks with a Yealink phone

How Does SIP Trunking Work?

What you may not realise is that SIP Trunking actually uses VoIP to place calls over a company's Internet Connection, rather than using traditional phone lines. SIP trunking works in tandem with VoIP Phone systems. However, where it differs is the fact that it still takes advantage of some traditional onsite hardware, such as PBX systems.

SIP Trunking eliminates all connections to your traditional phone company (PSTN) by removing the need for ISDN lines, hardware or circuit boxes – as well as the maintenance required to maintain the connection to the PSTN. The SIP 'trunk' is installed over your business' Internet connection instead. This replaces the need for an additional analog phone line.

Talk To A Cloud Enabler About SIP
Cloud, Hosted Desktop, VoIP and SIP use Ethernet connections

Will My Connection Support SIP?

Merging your multiple connections into your Internet connection means that you will need a robust connection. One with the right amount of bandwidth. There is a simple equation you can use to estimate the connection speed you will need. This will help you gauge whether or not your existing connection will be strong enough to accommodate SIP trunking, as well as your business' common Internet traffic.

Equation: (Number of peak concurrent calls) x 85kilobits per second = bandwidth in Megabits per second (Mbps) needed for calls

Are You A Channel Partner?

Are you an ISP or IT Support Company looking to integrate SIP into your portfolio? Or are you an existing Communications provider, looking for a strong and scalable Cloud infrastructure to build your own VoIP platform on?

Then Synextra’s Channel Partnership Programme is for you.

I Want To Know More

SIP Trunks Use Cases

There are many reasons why businesses switch to SIP over traditional ISDN, such as lower costs, greater security and business continuity – as well as the ability to take your number with you, even if your office moves across the country. Below are some of the main reasons businesses have recently switched over to SIP with Synextra:

Consolidate & Lower Costs

SIP trunks give you a high-quality voice solution over a single connection, rather than requiring multiple like with ISDN. This lowers your OpEx costs further, by reducing the number of connections you need for larger teams and device estates. Perfect for for large businesses and call centres.

So, if your business has multiple offices with multiple ISDN connections, SIP Trunks from Synextra reduces the number of ISDN connections your business requires as a whole.

Remote sites that no longer require an ISDN connection can pool their telephony traffic into a central PBX, meaning your business only has to pay for an Internet connection and the handsets at those sites.

Open Close

Fraud Protection

What you may not anticipate at the end of the month, is a large call bill landing on your desk because a disgruntled or opportunistic employee racked up hundreds of minutes to a private, high-call charge number.

Fraud protection safeguards your business from these unsavoury characters by monitoring your typical usage: finding any rogue calls and stopping them in their tracks.

Open Close

Disaster Recovery & Business Continuity

The two most important parts in any DR plan are the Recovery Time Objectives (RTO) and Recovery Point Objectives (RPO.) The RTO & RPO define A.) What mission critical systems need to be live and B.) How quickly they can be made live in the event of a disaster.

With instantaneous rerouting of calls to 'fall back' phone numbers, alternate offices and even mobile phones, you can ensure your telephony systems stay live – without the high costs of call forwarding associated with ISDN.

Open Close

Benefits of SIP vs ISDN & VoIP

SIP is a modern communications solution for modern enterprises. Save your business money by lowering call rates and I.T. maintenance required, as well as eliminating the costs of incoming phone lines. But how does it directly compare to traditional ISDN and fully-hosted VoIP solutions?

No Charges For Incoming Phone Lines Icon
No I.T. & Maintenance Fees Icon
Uses Existing PBX Icon
Easily Scalable Icon
Pay Per Line, Rather Than Bulk Icon
Optional Pay Per Minute Icon
Reroute Services For Redundancy Icon
Reroute to Mobile Icon

Cut To The Chase

Looking for a communications solution but, not sure where to start? Talk to one of our friendly Cloud Enablers and let us help you find your voice.

I Want To Talk About Voice Solutions

Break Free From Legacy Providers

VoIP from Synextra gives you all of the amazing features of SIP and even more. Plus, with everything hosted in the Cloud, you no longer need PBXs, further reducing CapEx costs.

I Want To Know More About VoIP