Codec - G729 Usage Limitations


As am using asterisk 16.4.0 (centos7 ) with SIP protocol as of now with u-law Codec between Asterisk Server to E1 SIP Gateway.

However am planning to use G729 Codec between these two endpoints. Here want to know any limitation/licensing problem.

Because as far as i seen G729 Codec available as free to download, but however digium providing license per channel basis, i don’t know how these calculation and how its working. What happen if used without licensing option.

Anybody help me on usage of this codec will be any legal complaint or something without license

E1/T1 is ISDN and I’ve never seen ISDN doing anything else than G.711, i.e. a-law and/or u-law. It doesn’t make much sense to use something else on other legs.

Am using Synway E1 Gateway which would connect E1 PRI on this. And also this gateway have support of various codec.
From this gateway asterisk connected using SIP Trunk. So basically i understand gateway doing transcoding from gateway to asterisk if ISDN doesn’t support.

And in my lab tested and working fine as well without any issue. My Question here whether its any legal usage or not mostly. And also which legs are all able to use this codec without any limitation.

G.729 is royalty-free since about 2017. I’ve never seen any necessity to support this codec, but it probably depends on the circumstances. If you (still) have an ISDN connection to the outside world, and the rest is inside your LAN, it is not worth the effort do deal with this codec.

For the avoidance of doubt, G.729 is significantly worse in quality than A-law or µ-law. It’s only benefit is reduced network bandwidth.

It is a 3.1kHz audio codec, so offers no frequency response advantage, and it is a vocoder codec, so it handles non-speech (music and tones) particularly badly). It is probably better than GSM, but you are not comparing it with that.

Ok. Got it.

@david551 , do u have any suggestion of free codec which is consuming low CPU & bandwidth without losing audio quality, non-speech usage other than A-law, u-alaw, where i feel high CPU and bandwidth which i worried about.

A-law and µ-law are have low CPU usage. Anything with lower bandwidth will sacrifice quality and use more CPU

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