Avada Slider: SIP Trunking

  • What are the benefits of switching to a SIP trunk service from ISDN?

    The move from ISDN to SIP trunking is a key step in preparing for the BT PSTN switch-off, scheduled for January 2027. As traditional telephony infrastructure is phased out, organisations must transition to IP-based services to maintain voice communications.

    Cinos experts Jono Darlington and Richard Evans explore the key benefits of moving to SIP — particularly for critical calling environments — in the following blog articles:

    In summary, switching to SIP delivers a range of benefits for organisations of all types, including:

    • Futureproofing: Ensures your organisation is ready ahead of the PSTN switch-off.

    • Lower costs: Reduced line rental, cheaper call charges, and fewer maintenance requirements.

    • Greater flexibility: Easily scale channels up or down and enable users to make and receive calls from any location.

    • Improved resilience: SIP trunks can automatically reroute calls in the event of outages, reducing the risk of downtime.

    • Faster deployment: No need for physical line installation, enabling quicker rollout and change

  • What is a SIP trunk service and how does it support business communications?

    A SIP trunk service enables voice calls to be made over the internet rather than through traditional telephone lines. It connects your organisation’s phone system or cloud unified communications service, such as Microsoft Teams or Webex, to the Public Switched Telephone Network (PSTN) using Session Initiation Protocol (SIP), allowing you to make and receive external calls through your existing IP-based infrastructure.

    SIP trunking supports modern business communications by offering:

    • Scalability: Easily add or remove channels as your needs evolve, without the constraints of physical lines.

    • Flexibility: Enable staff to make and receive calls from anywhere, supporting hybrid and remote working.

    • Cost savings: Reduce line rental fees, call charges and ongoing maintenance costs.

    • Reliability: Built-in redundancy and failover routing for improved uptime and resilience.

  • Why choose Cinos as your SIP service provider?

    Cinos is a Tier 1 SIP provider delivering a fully managed, end-to-end IP telephony platform with no reliance on third parties, so you benefit from lower call costs, reduced line-rental fees and predictable CAPEX. Our single-provider model ensures clear accountability and automatic rerouting in the event of connectivity issues, keeping your communications live even if a cable is accidentally damaged.

    Key advantages include:

    • Cost efficiency: Cheaper calls, lower line rentals and reduced maintenance overheads compared with PSTN. Our bundled minute offer includes unlimited SIP calling minutes to UK National (numbers starting 01/02/03) and UK Mobile (UK mobiles starting 07).

    • Unrivalled resiliency: IP-based rerouting automatically maintains service during faults or outages.

    • Clear ownership: A single partner for everything from handset to PSTN, eliminating delays in issue resolution.

    • Proven expertise: Seasoned project teams specialising in migrations for police forces, acute NHS trusts, hospitals and government departments.

    • Seamless migration: Meticulous planning and execution to minimise risk and downtime ahead of BT’s January 2027 PSTN switch-off.

    Whether you’re a critical-calling environment or any other organisation seeking reliable, high-quality telephony, Cinos combines technology, experience and accountability to keep your teams connected.

  • Is a SIP service suitable for hybrid and remote working environments?

    Yes, SIP services are ideally suited to hybrid and remote working environments. By routing voice calls over the internet, SIP allows users to stay connected from any location using their preferred communication platform. Cinos delivers secure, high-quality SIP connectivity that supports flexible working and integrates seamlessly with Microsoft Teams, Webex, and other collaboration tools.

  • How does a SIP service provider integrate with Microsoft Teams or Webex?

    Cinos integrates SIP services with Microsoft Teams or Webex using Direct Routing or cloud-based SIP trunking. For Microsoft Teams, this involves using certified Session Border Controllers (SBC) to connect Cinos’ SIP trunks to Microsoft 365, enabling users to make and receive external calls directly through the Teams interface. For Webex, Cinos connects SIP services via Webex Calling using a supported SBC to deliver reliable PSTN connectivity. Cinos works closely with your IT team to ensure seamless integration, optimal call quality, and alignment with your organisation’s telephony requirements.