VoIP - Hosted IP Centrex (HIPC)


Verizon’s HIPC solution is the winner of a 2006 Internet Telephony Excellence Award. The award, from Technology Marketing Corp.’s Internet Telephony Magazine, honors IP communications solutions that deliver innovation to customers. Verizon’s converged VoIP network allows customers to streamline voice, data, and Internet connections over one network, making it an ideal solution to help government agencies improving productivity. Verizon’s HIPC offers government agencies flexibility, efficiency, and affordability in an IP environment. In addition, HIPC delivers seamless telephony services and business continuity capabilities. HIPC also offers all of the features of a PBX or key system without the associated capital, lease, or maintenance costs. Like traditional Centrex, all PBX functionality resides within the Verizon network, eliminating the need for PBX infrastructure investments. In addition, this converged access, coupled with the dynamic bandwidth allocation feature, provides the capability to accommodate high-traffic periods—without the expense associated with excess capacity during non-peak times making it an ideal solution for seasonal, dynamic operations.



  • Enables the government to take full advantage of their existing investment in telephony equipment and Centrex service capabilities, while also delivering a platform for new productivity enhancing applications hosted by Verizon.
  • Eliminates the need for large infrastructure investments and maintenance costs.
  • Delivers a high quality, highly reliable, yet easy to manage and use telephony system.
  • Provides telecom managers with a desktop interface (Web browser) to manage everyday functions such as Moves, Adds, Changes, and Deletes (MACDs) as well as network applications.



Building upon the PSTN-based voice offering and IP trunking for interconnection to the PSTN, Verizon’s network-based Hosted IP Centrex architecture provides a seamless transition for the Government to both WITS 3 and converged technologies.

  • Call Processing Services/Application Services. Network-based servers provide call processing and call routing and translation policies that ultimately control traffic routing flows among Session Initiation Protocol (SIP) endpoints. These can either be dedicated SIP phones, gateways at the customer-premises, or shared VoIP gateways connected to the PSTN. The SIP Application Server (AS) delivers the enhanced personal, group, and media-based features that comprise HIPC service. This infrastructure, or VoIP service node, has resilient and secure network connections to the Verizon Multiprotocol Label Switching (MPLS) network.
  • Network Gateways. The VoIP service node access media gateway (labeled network gateway in the figure) is connected to the Public Switched Telephone Network (PSTN). These network devices provide conversion between VoIP and PSTN signaling protocols (i.e., TDM Pulse Code Modulation (PCM) encoding) for voice call origination or PSTN termination. The service provides the Government with support and interoperability via the following access methods:

Symmetrical Digital Subscriber Line (SDSL) 
at the following speeds:
• 384 Kbps
• 768Kbps

Internet Dedicated Access (IDA)
at the following speeds:
• T1
• T3
• Shadow (redundant) T1
• Shadow(redundant) T3

Private IP
at the following speeds:
• 384 Kbps
• 512 Kbps
• 768 Kbps
• T1
• T3