Characteristics of a bending-loss insensitive single-mode optical fibre and cable
Fiber Optical Cable
StatusIn force
Year started2006
Latest version4.0
November 2016
CommitteeITU-T Study Group 15
Related standardsG.651.1, G.652, G.8201
LicenseFreely available

G.657 is an international standard[1][2] developed by the Standardization Sector of the International Telecommunication Union (ITU-T) that specifies single-mode optical fiber (SMF) cable.


The G.657 Recommendation builds on a previous fiber optic specification in G.652.[3][4]

G.657 was first published in 2006. Revisions of the standard were since published in 2009, 2012, and 2016 (November).[5][6]


  1. ^ "Optical Fiber Types". www.thefoa.org. The Fiber Optic Association. Retrieved 2019-07-06.
  2. ^ "Large-Scale Production Technology for G.657 Fiber with Ultra Low Bending-Induced Loss". ResearchGate. Retrieved 2019-07-06.
  3. ^ "Reusing Singlemode Fiber? Here's What the G.652D and G.657A1 Standards Have to Say". www.belden.com. Belden (electronics company). Retrieved 2019-06-15.
  4. ^ CHANG, F. (2019-02-15). Datacenter Connectivity Technologies: Principles and Practice. Stylus Publishing, LLC. p. 36. ISBN 9788770220644.
  5. ^ "G.657: Characteristics of a bending-loss insensitive single-mode optical fibre and cable". www.itu.int. International Telecommunication Union. Archived from the original on 2015-09-01. Retrieved 2019-06-15.
  6. ^ "Your hardware order is ready. Do you want cables with that? | Network World". www.networkworld.com. Retrieved 2019-06-15.