SIP Trunking

One Connection to Global Communication

GTT’s SIP Trunking offering 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.

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 signaling and media with TLS and SRTP.

Comprehensive Global Footprint

GTT offers a full suite of international services, including DIDs, 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.

Meets Business Continuity Objectives

GTT’s SIP Trunking offering has built-in redundancy at the trunk level. Each customer is connected to dual GTT PoPs with redundant switching capability at each location. For enterprises seeking additional resiliency, we also offer a secondary failover option to an additional PoP or failover at the individual telephone number level, with routing based on time of day, site availability, traffic flow and more.

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
DIDs – 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 signaling and media with Secure SIP Trunking service option


Voice Services

Optimize collaboration across your business with our suite of cloud-based voice services.


SIP Trunking

Take your voice network to the next level and expand communication globally.


Hosted PBX

Take advantage of full PBX functionality delivered from the cloud.



REIMF increased data security and achieved cost savings by combining GTT’s SIP Trunking and MPLS network solutions.

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