High-quality SIP trunking connecting your PBX directly to our network via DSL or Ethernet. A flexible, modern alternative to ISDN with full codec and encryption support.
Blue Telecoms wholesale SIP trunking provides a high-quality, carrier-grade connection between your PBX and the public telephone network. Whether you're connecting over DSL broadband or dedicated Ethernet, our wholesale SIP service delivers the reliability and call quality your business demands.
Our wholesale SIP trunks are a flexible alternative to traditional ISDN lines. With ISDN being phased out across the UK, now is the time to transition to SIP — and Blue Telecoms makes that transition seamless. You get the same functionality as ISDN with far greater flexibility, scalability, and cost savings.
Whether you're a reseller looking for a reliable wholesale partner or a business with your own PBX infrastructure, our wholesale SIP service provides the foundation for rock-solid telephony.
PBX to network — direct and reliable
Choose the connectivity method that best suits your infrastructure and call volume requirements.
Connect your PBX to our SIP trunking service over your existing DSL broadband connection. Ideal for small to medium businesses with moderate call volumes. Our SIP trunks work reliably over ADSL, ADSL2+, FTTC, and FTTP connections with full NAT traversal support ensuring calls work seamlessly behind your router.
For higher call volumes and guaranteed quality of service, connect via dedicated Ethernet. Ethernet delivery provides a private, uncontended connection with guaranteed bandwidth and ultra-low latency — ideal for contact centres, large offices, and any environment where call quality is mission-critical.
BT is switching off the ISDN network by 2025, meaning every business still using ISDN will need to migrate to an alternative. Blue Telecoms wholesale SIP trunking is that alternative — providing everything ISDN does and more, at a lower cost.
SIP trunks replace ISDN channels on a like-for-like basis, but without the physical line constraints. Scale up instantly without waiting for engineer visits. Add or remove channels in minutes. Route calls across multiple sites without complex configuration.
Significantly cheaper than ISDN with per-second billing and no minimum charges.
Add channels in minutes — no engineer visits or physical line installations needed.
Port your existing numbers and transition smoothly from ISDN to SIP.
SIP is the standard for all future telephony — invest in a platform that will last.
Seamless transition to SIP trunking
Our wholesale SIP trunks support the same comprehensive range of codecs as our retail service, ensuring the best possible call quality across any network conditions or equipment combination.
High-strength voice encryption is available on all wholesale SIP trunks, ensuring your communications are protected from eavesdropping and interception. Our encryption meets the requirements of government and public sector organisations, making our wholesale SIP service suitable for even the most security-conscious deployments.
Full NAT traversal support ensures our SIP trunks work reliably behind any firewall or router configuration without requiring complex network changes. Simply configure your PBX and connect — we handle the rest.
Government-grade voice encryption
White-label our wholesale SIP trunking and offer it under your own brand. Competitive wholesale rates, reliable infrastructure, and full technical support so you can focus on your customers while we handle the network.
If you run your own PBX — whether Asterisk, Avaya, 3CX, Freeswitch, or any other SIP-compatible system — our wholesale SIP trunks connect you directly to the public telephone network with maximum quality and minimum cost.
High-volume call environments demand carrier-grade reliability. Our wholesale SIP trunks deliver unlimited concurrent channels with built-in PSTN failover, ensuring your contact centre stays connected no matter what.