Home Network Bridged Tap Test Solution For ID-337 Gfast Testing

Main Features

  • Simulates Home Network Bridged Tap topology specified in ID-337 Gfast standard
  • Compact Design
  • Support for Reverse Powering
  • Component of Telebyte’s Gfast Certification Testing Solution
  • Used by UNH-IOL for BBF’s Gfast Certification Test Plan
  • Download pdf


    product overview

    The Single-Line Performance Test in ID-337 requires a test instrument that replicates the Home Network Bridged Tap Test Loop Topology found in the standard. This topology consists of an isolated drop wire from the street to the house, known as the Network Termination Point (NTP). It also depicts in-home wiring of twisted pair cabling to 5 rooms, with the CPE connected in the room 20m away from the NTP. The other rooms are 2m, 2.5m, 5m, and 10m away from the NTP creating 4 bridged taps that are not electrically terminated and result in signal reflections of the Gfast signal traveling on each path. This produces attenuation distortion or “nulls” in the attenuation curve, based on the length of wire in each of the bridged taps. This “star” configuration affects the frequency bands used by Gfast (see diagram on next page). The HNBT-Starbox is a cable-based solution that uses CAD55 cable and provides the required test loop topology in one compact unit.

    Home Network Bridged Tap (HNBT) Topology

    The HNBT-STARBOX connections for ID-337 testing.



    25 kHz to 106 MHz (attenuation, impedance, group delay)


    MAE < 1.5dB

    Cable Simulated

    CAD55 as defined in TR-285

    ID-337 HNBT Cable Lengths Simulated

    Isolated Drop Wire (DPU to NTP): 100 m
    In-Premises STAR (Bridged Taps):  2m, 2.5m, 5m, 10m
    In-Premises NTP to CPE: 20m

    Support for Reverse Powering



    14” (355.6mm) x 14” (355.6mm) x 14” (355.6mm)


    CAT6 RJ45 x 2


    Specifications are subject to change without notice. Made in USA