G.fast is a digital subscriber line (DSL) protocol standard for local loops shorter than 500 m, with performance targets between 150 Mbit/s and 1 Gbit/s, depending on loop length. High speeds are only achieved over very short loops. Although G.fast was initially designed for loops shorter than 250 meters, Sckipio in early 2015 demonstrated G.fast delivering speeds over 100 Mbit/s nearly 500 meters and the EU announced a research project.
Formal specifications have been published as ITU-T G.9700 and G.9701, with approval of G.9700 granted in April 2014 and approval of G.9701 granted on December 5, 2014. Development was coordinated with the Broadband Forum's FTTdp (fiber to the distribution point) project.
The letter G in G.fast stands for the ITU-T G series of recommendations; fast is an acronym for fast access to subscriber terminals. Limited demonstration hardware was demonstrated in mid-2013. The first chipsets were introduced in October 2014, with commercial hardware introduced in 2015, and first deployments started in 2016