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Technical Specifications for Business Class PRI

Business Class PRI is a commercial ISDN trunk service that uses Internet Protocol (IP) technology to deliver data packets of voice signals over our fiber-rich network. It then converts the signaling to DS‐1 and provides PRI service via a voice gateway located at your business location. Your calls are never routed over the public Internet.


Our voice‐only, IP‐enabled service is delivered over our fiber-rich network. A single BC PRI offers customers a two‐way trunk with the ability to make and/or receive up to 23 simultaneous calls. The product provides customers with the standard ISDN PRI configuration of 23 B channels for voice communications and a D channel for signaling (e.g., 23B+D) as well as other fractional PRI service configurations.

Business Class PRI Specifications

  • Provisioned as a two-way, voice-only service
  • Bipolar with eight-zero substitution (B8ZS)
  • Voice encoding G.711
  • Framing is Extended Super Frame
  • Network Interface Device: RJ-48

Voice Gateway Specifications


  • Voice gateway emulates the ISDN PRI variants of NI-2, 5ESS, and DMS-100
  • Voice interfaces: 24 FXS analog voice ports or Four EHWIC slots depending on CPE