> For the complete documentation index, see [llms.txt](https://prosbcdocs.telcobridges.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prosbcdocs.telcobridges.com/telecom-references/voice-and-media/gsm-efr.md).

# GSM-EFR

GSM-EFR, also known as Enhanced Full Rate, is an audio compression standard used in GSM mobile networks.

### TelcoBridges and GSM-EFR

TelcoBridges supports GSM-EFR encoding and decoding. Due to patents, a software license is required to use it in a production environment.

The following options are available:

* packet duration options of 20, 40, and 60 ms
* one bit rate for GSM-EFR: 12.2 kbps

### References

* [Wikipedia article](http://en.wikipedia.org/wiki/Enhanced_full_rate)


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