VoIP IP Trunking through SIP Trunking Interfaces


Verizon Business’s IP trunking is a standards-based SIP trunking interface trunk designed to work with any IP PBX that supports SIP-based trunking. Verizon Business requires successful completion of certification testing of an IP PBX platform since there could be variations in vendor implementation and possible effects on quality and performance. This involves careful analysis to identify and resolve potential interoperability/support issues prior to attesting that the platform works with Verizon Business’s VoIP IP trunking service. Verizon Business can support SIP trunking on multiple providers through access methods such as IP trunking.



  • Leveraging Verizon Business’ Technology. Verizon Business’s IP backbone will be used to route calls to and from the Public Switched Telephone Network (PSTN) via the SIP trunk(s).
  • Network-Based Support. Use the network-based private dial plan for enterprise on-net calls.
  • Flexibility. Provides government agencies with the option to gradually replace TDM voice circuits and fully leverage their converged WAN network.
  • No Need to Retrain Employees or Experience Disruption in Service. Verizon Business’s VoIP service retains all the current IP PBX features. There is no need to retrain employees on any of the calling features or functions and no need for equipment changeover or disruption to services.



Through the use of SIP trunking technology and network-based servers, IP Trunking provides telephony signaling and transport of a subscriber’s voice traffic over Verizon Business’s MPLS networks.

Establish and Receive Calls. IP Trunking allows a subscriber to successfully establish and receive telephone calls between on-net locations and establish/receive calls between on-net and off-net locations by interoperating with the PSTN.

Interoperability. IP Trunking supports interoperability with Ethernet Local Area Networks (LANs), legacy telephony equipment (e.g., PBXs, key systems, Purchase of Telecommunications Services (POTS) phones, facsimile machines, and modems) through the use of premises- and network-based gateways. A digital trunk, or enterprise, gateway allows a subscriber’s PBX to connect to the IP trunking network, while an analog trunk gateway allows a subscriber’s key system, POTS phones, fax machines, and modems to connect to the IP trunking network.

IP Trunking has the following access types:

  • Internet Dedicated Access (IDA) at the following speeds T1, T3, shadow (redundant) T1, and shadow (redundant) T3.
  • Private IP at the following speed 384 Kbps, 512 Kbps, 768 Kbps, T1, MLPP/NxT1, and T3.

Quality of Service. IP Trunking uses a standards-based quality-of-service scheme based on the IEEE 802.1 p/q standards to provide a high-quality of service while mitigating call quality issues. Verizon Business provides industry leading Service Level Agreements (SLAs) that include Mean Opinion Score (MOS), jitter, packet delivery, network availability, and Denial of Service (DoS).

Services are not available in all areas. Please consult your Verizon Business representative for service availability and complete details.