Our SIP Trunk Solution
We can help your business install top-of-the-range SIP trunk solutions through a complete end-to-end service, dedicated to providing you with the very best call quality, network performance and ease of management.
Our SIP trunk solution include:
- Setting up a brand new SIP trunk network for your organisation, or converting a previous ISDN setup over to SIP trunks
- Helping you port your existing phone numbers over to the new network
- Integrating your new SIP trunk setup with communication software and tools such as Microsoft Teams and Cloud 3CX
- Introducing you to the many features offered by your upgraded connection, from voice, video and messaging applications to desktop sharing, web conferencing and shared whiteboards
- Providing ongoing network management support to ensure stable, reliable and high-quality call services
No matter what your needs may be, we can work with you to create a bespoke SIP trunks setup that meets all of your requirements, in terms of technical performance and functionality, while also ensuring your business is able to take full advantage of the new software tools and network capabilities available to you.
What is SIP Trunking?
SIP (session initiation protocol) trunking is an innovative form of telephony that connects your company’s phones to the public PSTN telephone network via internet-based data transfer and VoIP (voice over internet protocol), rather than through the traditional phone lines.
With SIP Trunking this means your phone services are no longer tied to any local exchange, meaning you can choose phone numbers without being linked to any specific region, as well as avoiding conventional calling charges. Data-based calls also offer a better sound quality, easier call recording and more seamless integration alongside systems like Microsoft Teams.
SIP trunks are a direct successor to older ISDN lines, with an increasing number of businesses shifting from ISDN to SIP trunk-based telephony in recent years.

Business benefits of SIP trunk solutions
By switching to SIP trunks for your business, you can unlock a host of advantages that range from substantial cost savings to enhanced flexibility and advanced communication features.
Enjoy many IP features
Converting to SIP trunk enables your legacy phone systems to benefit from a whole host of modern IP features, including:
- Enhanced functionality, including improved support for video messaging, conference calls and media sharing
- Call recording provided via SIP, rather than at at private branch exchange (PBX) level
- Create new fixed-line numbers for your business with local area codes, rather than being limited by your geographical location
- Reduced costs on lines coming into the business when numbers are ported
Save multiple costs
With a suitable internet connection – whether supplied and managed by Fuse 2 or an existing solution – SIP trunks enable business voice calls to be routed through the internet via the Fuse 2 carrier-grade network, delivering competitive call rates, even for international calls.
For legacy systems that do not allow VoIP, Fuse 2 can install and manage ISDN conversion units that convert analogue calls to SIP, without affecting any aspect of the existing system. This eliminates unnecessary expenses such as hardware purchases, installation and maintenance costs.
Future-proof your phone setup
The traditional ISDN phone network is set to be turned off entirely in the next few years, with an expected date of 2025 set in the UK. By converting to a modern voice solution now, you will be protecting any future investments you make within your communication network, and ensure you will be ready for the future of business communications.
How can fuse2 help with your SIP Trunking?
We deliver the highest quality of SIP Trunk solution for your business. As an award-winning independent provider of communication services for organisations all over the world, and can work flexibly to find the very best solution for you.
as your trusted SIP trunk provider, we will unlock your world of communication.
Fully managed end-to-end service
You can work with a single trusted provider over all aspects of network usage, accessibility, security and monitoring

Enterprise-grade network
We proactively monitor via sophisticated bespoke software providing us with clear performance metrics for your peace of mind.

Guaranteed Call Quality
A highly diverse carrier network that allows us to guarantee call quality and each segment of our voice platform to operate regardless of interconnect outages

Transparent oversight
Oversight on all equipment, with notifications sent to engineers to ensure the end user is notified of potential disruptions or issues before they have even been noticed

Talk to the SIP Trunk Solution Experts
Setup your SIP Trunk Today
We’re a fully independent company that provides the same quality of service as a big brand, meaning you will always receive friendly and personalised customer service from us, with a focus on custom network solutions tailored to your specific needs.

SIP Trunk Solution FAQs
What’s the difference between SIP and VoIP?
SIP (Session Initiation Protocol) and VoIP (Voice over Internet Protocol) are related and are often used together in modern communication systems, but they both serve unique purposes. Here are the key differences between SIP and VoIP
VoIP (Voice over Internet Protocol):
Broad technology for transmitting voice, video, and communication over the internet.
Encompasses a range of protocols, including SIP.
Used for various communication services like voice calls, video conferencing, and messaging.
Examples: Skype, WhatsApp.
SIP (Session Initiation Protocol):
Specific signalling protocol for initiating, controlling, and terminating communication sessions in IP networks.
A subset of VoIP, focusing on session setup and control.
Primarily used for voice calls, video conferencing, and real-time communication.
Example: Used to establish and control calls, while VoIP handles actual data transmission.
Is there a limit on how many phone numbers I can have?
There is no limit on the number of phone lines with SIP trunks, making it highly scalable for businesses of all sizes.
How many concurrent calls can a sip trunk handle
The number of concurrent calls a SIP trunk can handle depends on several factors, including the capacity of the SIP trunk, your network infrastructure, and your service provider’s offerings. Contact our expert SIP Trunk team for more information on your SIP requirements.
Why do i need a SIP trunk
SIP trunks are a cost-effective alternative to traditional phone lines, offering substantial savings on long-distance and international calls. They provide scalability, allowing you to easily adjust the number of concurrent calls to match your business’s growing communication needs.
SIP Trunks promote business continuity with features like disaster recovery, ensuring your operations remain accessible even during network disruptions. We help modern businesses with streamline communication, reducing costs, and improving overall efficiency.
How do SIP Trunks Work
SIP trunks, or Session Initiation Protocol trunks are the backbone of modern business communication systems by facilitating VoIP and multimedia services over the internet. When a call is initiated, SIP trunks create a virtual “session” and use SIP signalling to establish a connection between your caller and you.
This signalling involves the exchange of SIP messages, like requests and responses, to initiate, maintain, and terminate the session. SIP also handles multimedia session descriptions and parameter negotiations during setup, such as choosing codecs and encryption. Throughout the call, SIP remains active, controlling features like call forwarding and monitoring the session.
As the call concludes, SIP signalling is used to gracefully terminate the session, ensuring that resources are freed up for future calls. Call Detail Records (CDRs) are often kept for billing and analysing performance of networks as you develop your business you may need to upgrade in the future.