SIP Trunking

Save up to 40% on your phone bill with a SIP trunk from Dia Telecom. Our SIP trunk simply replaces your existing analogue PSTN- or digital ISDN lines. Technically nothing changes on your end, while preserving the highest availability and all the features you are used to.

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Get more out of your communications

An increasing number of corporations consider a switch to SIP, not only for its greater flexibility and immediate costs savings, but it also helps optimise their network investment.

SIP (Session Initiation Protocol) is an open standard technology that allows you to make calls over an IP connection, rather than a traditional phone network.

Thanks to the SIP protocol solutions like Voice and Video over IP have conquered not only a place in the private segment, but it also forms the cornerstone for communication solutions for corporations.

As one of the first providers Dia Telecom came with solutions that use open standards and comply with the requirements of the market. In the development of our SIP based products our years of experience in the field of voice, video and data has been decisive.

Our SIP trunk brings you the benefits of Voice over IP (VoIP) while retaining your telephony exchange equipment at your location.

Dia Telecom has a proven record of providing excellent service and reliability. Our SIP trunk delivers the best of both worlds, saving costs without compromising on call quality.

As a wholesale provider we handle large amounts of traffic for the Corporate Market, connecting people through high redundant Intelligent Networks for maximum availability.

Microsoft Skype for Business

As a Skype for Business (SfB) Trunk Provider, we want to make sure your setup and implementation is easy, quick and painless.

Our SfB trunk natively connects to your Microsoft SfB platform. This means that no extra gateways/routers are required to establish a connection between SfB and the SIP service.


Our Skype for Business trunks are supported and qualified through Microsoft testing standard.

  • Native Connectivity
  • Fast and Easy Service
  • Enhanced Encryption
  • Tested and Approved

Free trial with all features

Once you supply us with the information we need, your SIP trunks can be up and running in as little as 30 minutes!

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True mobile integration

One of our latest developments was made to improve the accessibility of mobile- and remote working employees by incorporating the Forced-On-Pabx interconnects.

It’s simple, no App or smartphone is needed. By replacing your Sim card, your mobile phone literally becomes an extension of your desk phone.

This means that you can be reached on you mobile by colleagues via your fixed extension and you can call colleagues by dialing their extension.

Your mobile presence is shared throughout the organization and you have one single voicemail for fixed and mobile coverage.

And the best thing is that your high mobile phone bill belongs to the past since all mobile calls are handled through landlines.

  • Share mobile phone presence with colleagues
  • Exchange calls between desk and mobile phones
  • Desk and mobile phone ring at the same time
  • Dial extensions on your mobile to call colleagues
  • One voicemail for fixed and mobile coverage
  • Alle types of mobile phones are supported
  • No smartphone or App is needed

Amazing Benefits

Besides immediate costs savings and greater flexibility we introduce more amazing benefits.

Suitable for all types of telephone exchanges

Even when your Pabx equipment is not prepared for SIP, we fit a local VoIP adapter to your equipment to convert our SIP trunk into traditional PSTN- and/or ISDN lines.

Microsoft Skype for Business compliant

Our SIP trunks are certified and ready to connect to your SfB server. Get off to a flying start, we have taken all the guess work out of the integration.

Inter branch office calls free of charge

By implementing SIP trunks throughout your branch offices your inter branch office calls become free of charge.

True Mobile integration

Our Forced-On-Pabx (FoP) solution connects your SIP trunk to our mobile communications platform. Thanks to this connection, all the facilities that you are used to on your landline will also be available on your mobile phone(s).

Superior voice quality

Thoughout our telephony network we use the G.711 codec. This carrier class codes ensures a crystal clear speech quality, it requires less complexity and reduces transcoding.

Add more features and services

You can easily add innovative features such as Interactive Voice Response, Aura Messaging and Call Waiting.

No analog PSTN and/or ISDN lines needed

Start saving on your monthly fixed costs since analog PSTN- and/or ISDN lines are no longer needed. While your existing telephone and facsimile numbers remain unchanged.


With your SIP trunk in place you can easily migrate to our Unified Communications as a Service (UCaaS) solution when your telephony exchange equipment becomes depreciated.

24x7 highest availability

Our SIP network interconnects are distributed over different data centres to ensure that your telephone service is available 24 hours a day, 7 days a week.

More for less

Many business owners only think about saving on their telecommunications expenses when they have to invest in new telephone exchange equipment.

However, you can substantially reduce the costs of telecommunication with a SIP trunk from Dia Telecom. Even when your current telephone exchange needs no replacement and/or is not prepared for SIP trunking.


Save up to 40% on your phone bill with a SIP trunk from Dia Telecom.

  • Suitable for all types of telephone exchanges
  • Adapted to latest technology
  • True mobile integration
  • Get more features and services
  • Grows with your business needs
  • 24/7 highest availability

What You Get

We take pride in delivering the best SIP trunk solutions with amazing flexibility and costs saving benefits.

Quality Of Service

Our SIP trunks provide Quality of Service to guarantee that packet traffic for a voice or other media connection will not be delayed or dropped due interference from other lower priority traffic.

Superior Voice Quality

Thoughout our telephony network we use the G.711 codec to ensures a crystal clear speech quality, it requires less complexity and reduces transcoding.

24x7 Nectar Monitoring

Our SIP platform and network performance is monitored by our Nectar Voice Quality Monitoring system which uses thresholds for delay, jitter, and packet loss, calculating MOS values to evaluate relative call quality.

24x7 Highest Availability

Our SIP network interconnects are distributed over different data centres to ensure that our SIP telephony service is available in accordance with our Service Level Agreements, all with suitable layers for security and compliance.

Managed CPE

Throughout our network up to our customer's premises we solely use proven technology Cisco equipment which is installed, managed and monitored by our professional team of engineers.

Telecom Expense Management

On a monthly basis you receive a clear and extensive report based on our Call Detail Records (CDR's). This enables customers to place their expenses on branch offices, departments, campaigns or even on specific employees.

Customer Testimonials

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