What's SIP Trunking?


If you’ve wondered what “SIP Trunking” is, you’re not alone. To better understand SIP Trunking, it helps to define both “SIP” and “trunking” separately.

“SIP” (Session Initiated Protocol) is the industry protocol that defines signaling operating standards for initiating interactive user sessions over a data connection. A “trunk” is a circuit between switching systems that can carry a specific number of calls at a time. “SIP Trunking” offers a VoIP connection between the customer’s IP PBX and Windstream’s next generation softswitch, capable of carrying one or more concurrent calls, routed over the customer’s data connection. Basically, SIP Trunking offers a modern alternative to traditional TDM trunks, improving the utilization of network capacity.

Advantages of VoIP

  • Convergence: Offers your business a combination of voice, Internet and networking services.
  • Dynamic Bandwidth: Provides true bandwidth allocation as channels on the T1 alternate “on demand” between voice and Internet.
  • Future Growth: Enables you to scale with minimal expense by eliminating the need to buy costly PRI cards.
  • Voice Prioritization: Ensures the calls coming into and going out of your business always receive priority.
  • Quality of Service (QoS): Ensures the highest quality of service, like Windstream’s QoS that leverages state-of-the-art, fully-redundant IP network and on-premises integrated access devices.

Benefits of SIP

  • Centralized Access: SIP Trunking allows main and branch offices to share hardware and access at the primary site when partnered with VPN Real Time MPLS WAN solution. Supports local calls and 911 routing in service area, as Windstream does within the Windstream footprint.
  • Cost Efficient: Dynamic bandwidth allocation and the SIP Trunk compression feature work together to provide the most efficient use of bandwidth.
  • Robust Features: Features such as Compression (G.711 and G.729) also allow for improved utilization of bandwidth.
  • Survivability: Trunk-to-Trunk overflow allows for multi-location survivability.
  • Reduced Capital Expense: IP PBXs save capital expense by not requiring customers to buy PRI cards for growth.
  • Future Growth:Most top-of-the-line IP PBX are future-proof and offer next generation features such as:
    • Mobile Applications
    • Call Center Support
    • Accounting Applications
    • Call Recording

Increasingly, businesses are recognizing the flexibility and cost-savings of VoIP access and SIP Trunking services and are using media gateways to connect IP-based services to existing telephone systems. VoIP access and SIP Trunking services are also becoming the logical choice for businesses migrating to a unified communications infrastructure.

If you’re considering a SIP Trunking solution, Windstream’s now the market leader, recognized by the independent industry consultants at Frost & Sullivan as one of the largest VoIP and SIP Trunking providers in North America in 2012. We’re confident we can help you find the most reliable, cost-efficient communications solution to meet your unique business needs.