So, I have an interesting (and very frustrating) one for you guys. I am using CME with Broadvox for a SIP trunk provider and have 7975g phones internally. I would like to have them use G722 on any call where it's possible and G711 on all other calls. Broadvox support claims they (the company, not the phones) only support G711, but various pieces of their documentation states they also support G722. I haven't tracked that down yet, but I would like the phones to use G722 internally, at the very least. I really see no draw back to it since it uses the same bandwidth but offers much improved clarity and the phones are supposed to be HD capable. So, I am aware there are certain commands you have to enter in the router to enable G722 in CME, including:
telephony-service
codec g722-64
service phone g722CodecSupport 2
service phone handsetWidebandEnable 1
service phone headsetWidebandEnable 0
service phone handsetWidebandUIControl 0
service phone headsetWidebandUIControl 0
service phone advertiseG722Codec 1
Setting these in telephony-service yields the following settings on the phone:
Wideband Headset
Enabled
Enterprise Advertise G.722
Disabled
Device Advertise G.722
Enabled
As I understand it, simply setting the default codec should get the phones to use it at this point... This is not the case...
Again, as I understand it, simply using "codec g722-64K" in the "voice register pool" for the phone should set the primary codec to G722, but if the other end doesn't support it, it will fall back to G711 automatically. Doing this yields "<preferredCodec>g722-64</preferredCodec>" in the config file that CME generates and causes the phone to list G729a as it's primary codec. The phone works as expected, just without ever using G722.
Setting "codec g711ulaw" in the "voice register pool" for the phone yields "<preferredCodec>g711ulaw</preferredCodec>" in the config file, and the phone lists it as the preferred codec with everything working as expected, just without G722.
Trying to force the issue, I set "voice-class codec 1" in the "voice register pool" for the phone and created the voice class codec list:
voice class codec 1
codec preference 1 g722-64
codec preference 2 g711ulaw
The configuration file then lists "<preferredCodec>g722-64</preferredCodec>" in the configuration file with no mention of G711, but the phone lists G729a as the preferred codec and like the first case I listed, negotiates G729a between phones with the same configuration, and G711 with my standard "codec g711ulaw" configuration as well as outbound through the SIP trunk, which is set to use G711. Again, the phone never uses G722...
I've seen some configuration files around the web that people say came from CCM and they generally list "<preferredCodec>none</preferredCodec>" on phones that are using G722. As CME puts "<preferredCodec>g729a</preferredCodec>" in the configuration file when you totally remove codec configuration from the "voice register pool", I manually edited the configuration file for a couple phones I'm using for testing to that configuration and the phones suddenly started using G722 (for absolutely everything, I might add, as per the call statistics on the phone). The problems are that I can't get CME to place that in the configuration files itself, so any time I make a change to configuration and regenerate the files, I'm going to have to manually edit every single phone to get it to have that configuration and the phones randomly decided to stop using G722 after some time making test calls. Even after a factory reset, I couldn't get them to use G722 again.. Also, with this configuration and while they were still using G722, all outbound calling scenarios from these phones worked (Exchange voicemail, internal phone to internal phone, outbound on the trunk) but inbound calls from the trunk failed as soon as the receiver is picked up. I have confirmed that DSP resources in the router were transcoding internal calls that needed it as well as outbound calls through the trunk, but were for some reason failing to transcode incoming calls that needed it, since the phone didn't seem to want to fall back to G711 at any point at all..
I'm stumped here.. I'd really like to get this working 100% so I can get my system ready for the day when G722 is broadly available on the market as well as to yield the benefits of it internally and intraoffice (as well as for clients in the future). I am currently running SIP75.9-3-1SR1-1S on the phones in question and c2900-universalk9-mz.SPA.153-3.M on the router I'm performing the testing on. I'm guessing that I'm either missing something or there are bugs in the firmware.. Any assistance would be very much appreciated.
