Sales Enquiries:

+44 (0)207 029 4800

General Enquiries:

+44 207 029 4800


+800 4683 7681

Sales Enquiries:

[email protected]

General Enquiries:

[email protected]


[email protected]

SIP Trunking

One Connection to Global Communication

GTT’s SIP Trunking goes beyond voice transport, transforming how enterprises do business. From voice to video to instant messaging, we help you drive productivity and efficiency organization-wide through seamless integration of diverse communication capabilities.

Features & Benefits

  • Flexible and Secure

    Our SIP Trunking offering is interoperable with all major UC platforms, including Skype for Business, Avaya, Cisco, Siemens and ShoreTel, and can be seamlessly integrated with legacy equipment. We also provide a secure SIP Trunking service option that guarantees encryption of sensitive call signalling and media with TLS and SRTP.

  • Comprehensive Global Footprint

    GTT offers a full suite of international services, including DDIs, toll-free, termination and emergency services, providing expansive reach on a global basis. Our global, fully redundant and robust SIP-based network has been specifically designed to meet the demands of bandwidth-intensive communication services.

  • Drives Cost Savings

    SIP Trunking is capex-efficient, eliminating the need for public switched telephone network (PSTN) gateways and ISDN BRIs or PRIs. The service also reduces local and long-distance costs as site-to-site calling is included at no charge. Furthermore, SIP Trunking provides bundled options to include per-minute usage in the monthly service charge.


  • Diverse global communications services integrated onto one connection

  • Interoperable with key UC platforms and legacy infrastructure

  • Global SIP-based voice network, which includes industry-leading Sonus Session Border Controllers for easy scalability

  • Comprehensive telephony footprint

    Termination — 200+ countries and territories

    DDIs — 65+ countries

    Toll free — 120+ countries and territories

    Emergency services — select countries outside the U.S.

  • In-country international voice testing, available in 105+ countries and territories

  • Highly redundant offering, with failover at trunk or telephone-number level

  • Encryption of sensitive call signalling and media with Secure SIP Trunking service option

Related Services
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  • SD-WAN

    Transform your WAN with dynamic network traffic management

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  • Managed Network Services

    Comprehensive offering including network monitoring and CPE full life-cycle management

    Learn More

Learn more about how GTT can help your enterprise propel collaboration, mobility and growth.

Contact Us