G722 HD Codec for PRI / FXS Ports

[Anonymous]

We understand that HD voice conversations only work when both ends speak a wideband codec, and both ends have devices capable of recording and playing wideband codecs. I know the Adtran 900/900e's support the HD G722 wideband codec. I know how to specify this codec as the first to use in the configurations.

My questions is will G722 work overs FXS or PRI ports on the Adtran Total Access 900/900e?

I believe the PRI protocol supports wideband codecs. I am not sure about analog FXS ports supporting wideband, but this looks like its capable:

Graves On SOHO Technology » New TIA Standards For HDVoice Over Analog Jacks

The idea would be to have two clients on the network communicate over HD wideband. Once client has hosted PBX with us using Polycom VVX 500's connected to a Broadsoft switch. The other client has a NEC PBX onsite, Adtran 900e converting a SIP trunk from the Broadsoft to a PRI port going to the NEC PBX. Would either notice a difference in call quality?

I know g711 and g722 use the same amount of bandwidth, so there is no problem there. The Broadsoft has an Acme packet that does transcoding to G711 for PSTN calls, so there is no problem there either. I know that G722 supports all the frequencies of G711 as well.

Is there any reason not to do this? I know all calls to the PSTN will be G711 so the Acme packets will have to do much more transcoding work, but I don't have to pay for the Acme packets. 

[Anonymous · Accepted solution]

Fiberman,

While it's true that our IPBG's have a G.722 (HDVoice/Wideband) audio codec option, this only applies to SIP-to-SIP calls, not TDM-to-SIP (or vise-versa.)  However, If wideband audio is possible over TDM connections (e.g. Analog FXS, FXO, or T1/PRI), it would require not only wideband/G.722 support in the DSP; but in the SLIC of the analog interface as well --- (Neither of which are currently supported in our IPBG's).  Our G.722 codec option simply allows a G.722 "SDP Offer" (generated by an endpoint capable of supporting wideband audio) to pass when the IPBG is configured as the UAS (User Agent Server) or SIP Registrar. Otherwise, all G.722 SDP Offers would be dropped by the IPBG and never passed to the far-end UAC (User Agent Client).  That being said, I'm not aware of any plans to implement G.722 support in our DSP or SLIC's.

- Burgermeister

[Anonymous]

Thank you for the detailed answer!