The story behind Gfast Certification

Ensure multi-chipset interoperability between solutions

  • Certification demonstrate interoperability between multiple chipsets and product combinations

Made possible by 1000s of hours of close technical collaboration and teamwork by the participants and UNH-IOL

  • Rigor or IR-337 has taken certification testing to a new level for the industry
  • Represents an outstanding technical achievement
  • 30 rigorous tests of the stability, functionality, control, and performance of Gfast
  • Years faster than previous access certification

NOTE: As of July 2018 the list of certified interoperable products is available on the University of New Hampshire InterOperability Laboratory’s web site. This live site allows real-time availability of certification changes and easier views of interoperable products. Click here to visit see the list on the UNH-IOL site

To have your Gfast DPU and/or CPE products tested and added to this growing list, please contact the official testing laboratory: University of New Hampshire InterOperability Laboratory

Gfast Certification Guidelines (OD-362) are available on the BBF wiki. Click here.

Gfast Certification overview

Test plan defined in Broadband Forum’s IR-337

  • Three key areas of focus: baseline performance, stability, mandatory features

Verification of key features within Gfast

  • Bit-swap, FRA, SRA, RPA, Retransmission, Test Modes, PSD control, TIGA, RFI controls, verification of performance counters

Basic assurance of performance

  • Required operation in noisy conditions
  • Required bit-rate vs. distance
  • Mean time between errors (a.k.a. stressed receiver)

Certification: IR-337 elements

Seamless Rate Adaption (SRA) shifting

  • Allows the Gfast line to adjust the bit rate to changing conditions while giving the customer the fastest possible connection.

First Rate Adaption (FRA)

  • Gfast specific stability feature allows line to survive large, sudden changes, preventing unneeded retrains and unavailable time.


  • Allows the line to re-transmit data that would normally have been discarded, improving the user’s quality of experience.

Basic minimum level of performance

  • Ensure the CPE or DPU can provide data rates needed for ultra fast broadband (>600Mbps)

Verification of spectral compliance, to avoid interference with equipment FM radio, etc

  • Broadband Forum PHYtx Work Area developed detailed test procedures for testing a variety of devices and chip sets.

With reference to the ITU-T specifications:

  • PSD testing ensures a device will not negatively impact other systems, by violating the required mask defined in G.9700
  • Testing conformance to transceiver functions, such as data transmission, seamless rate adaption, fast rate adaption, bit swap, re-transmission, TIGA, etc., as defined in G.9701
  • Certification tests the control, status, and performance parameters used to configure and monitor lines (See also TR-355 Yang models) as defined in G.997
  • The Program’s certification has played a significant role in understanding and improving the implementation of Gfast