|
Who uses what Codec?Is there a list out there with as many providers as possible and the codecs they use? To me this is the most important aspect since it determines both the quality of the call and how much bandwidth you need, yet I've been very unsuccessful in finding this information. Thanks for any help. |
|
|
I have 4MBit down/750Kbit up and I use ULAW and G729 depending on which service I use. |
|
1 edit
3 recommendations |
to wiggles4
I don't know of any such list but I see no reason we can't make one. I will try to keep this post updated with the information. Right now I can fill in the following.
Vonage: G.711/G.726/G.729 Broadvox Direct: G.711/G.729 + T.38 Packet8: G.729 (G.711 Fax) AT&T Callvantage: G.711 Broadvoice: G.711 VoicePulse: G.711/G.726-32/G.726-16 Lingo: G729 + T.38 FWD: G711 Voiceline: ? Iconnecthere: ? Quantum Voice: G.711/G.729
----- [Edited by request. --kc] |
|
|
Thanks, nsumner. That actually clears up most of the companies I was unsure about. I thanks to the mods for sticking this. I was a bit disheartened when I saw it fall to the third page after half a day. |
|
sgarrandInsert Witty Phrase Here Premium Member join:2000-04-13 West Brookfield, MA |
to nsumner
said by nsumner: Quantum Voice: ?
That would be G711u and G729a for QuantumVoice. You can choose and use either in the SPA-2000 config for their service. Scott |
|
|
ok, so where can we find info on wich codec offers the best voice quality ?
Thanks in advance,
Adi |
|
|
sgarrandInsert Witty Phrase Here Premium Member join:2000-04-13 West Brookfield, MA
1 recommendation |
sgarrand
Premium Member
2004-Oct-16 9:39 am
Try this site: » www.voip-info.org/wiki-CodecsThere is a lot of information out there about codecs. This thread also mentions more links: » [Primus] What determins GOOD voice quality?Scott |
|
|
to wiggles4
Here are some example of voice quality MOS (Mean Opinion Score) scores collected before. G.711 has the best voice quality. However, you need to pay for the price of high bandwidth.
1. PSTN switch: MOS is closed to 4.5 2. G.711 A/M: 4.4 or up 3. G.729: About 4.0 4. G.723: About 3.5 5. G.726: If I remember correctly, depend on its rate, the score is between 3.5 to 4.3. |
|
magm58 join:2000-07-12 East Elmhurst, NY |
to nsumner
nsumner for you info Broadvoice is using the codec G711u |
|
|
to wiggles4
Hmm, I can't go edit my post to add Quantumvoice. I am also looking for confirmation on what Codec Broadvoice is using. I was told a while ago they switched from G.711u to G726-32, can anybody confirm what they are using (okay okay okay I shall send them an e-mail). |
|
gtj join:2001-12-10 Arvada, CO |
to wiggles4
|
|
digiblur Premium Member join:2002-06-03 Louisiana |
to wiggles4
Nothing like the hearing the difference of G.711 I compared the quality of P8 and VP next to each other for a while and kept finding myself picking up the VP line instead of the P8 line. The main difference I found was I didn't find myself "stepping" on the other persons conversation. We didn't get the "go ahead" "go--" "you go ahead" type thing you hear from talking in between two different digital cell phone providers. |
|
|
daguy to wiggles4
Anon
2004-Oct-26 1:19 am
to wiggles4
mutualphone - g.729 |
|
ieee1394 Premium Member join:2001-08-25 Corte Madera, CA |
to digiblur
said by digiblur: The main difference I found was I didn't find myself "stepping" on the other persons conversation. We didn't get the "go ahead" "go--" "you go ahead" type thing you hear from talking in between two different digital cell phone providers. It's odd that there hasn't been much discussion about this side effect that can sometimes occur. I think it's related to jitter. While either listener may be hearing great audio quality the fact of the matter is that if there is excessive jitter during the connection (usually caused by latency) then the audio will actually be "played back" (as it were) with enough timing difference that you will start stepping over each other's conversation without knowing it until both parties try to talk at more or less the same time. The other problem that often comes up is that one person in a conversation is speaking and the other wants to interrupt. But for some reason or another it's like the other party doesn't hear the interrupting party at all. |
|
|
said by ieee1394: The other problem that often comes up is that one person in a conversation is speaking and the other wants to interrupt. But for some reason or another it's like the other party doesn't hear the interrupting party at all. This can also be due to Voice Activation Detection ("VAD"), which is totally independent of Codec. This is a bandwidth-saving feature that suppresses transmission of the audio signal until it detects sound. It conserves bandwidth, but causes a slight delay in the transmission. |
|
|
to wiggles4
I use the G.711 on a 400/256k connection scored a 4.1 MOS , 4.4 was the best. » www.testyourvoip.com/det ··· d=HX2FJY |
|
Walla join:2004-02-26 Israel |
to wiggles4
MSM Netphone uses 711 and 726 - soon to have 729! |
|
|
to wiggles4
maybe these guys can help - » www.downetworks.com |
|
pcmeetOfficial Dta Guru join:2003-09-15 Montgomery, AL |
to nsumner
Anyone know what codec sipphone.com uses ? I have the dialup sip phone DUV-1000 uses G.729 and want to see if it will work with sipphone. |
|
|
to wiggles4
Voz Online - G729a we use this Codec because of ots extreemly low bandwidth usage, we have tested all of the available codecs and have come to the conclusion that the g729a has excellent efficiency |
|
priller join:2000-10-20 Gainesville, VA |
to wiggles4
SunRocket --- G.711 |
|
|
to wiggles4
I also asked about the codec for SunRocket, and the rep was unable to confirm this, but he said others also asked, and he thinks they use G.711. |
|
lyulyok Premium Member join:2004-04-15 Seattle, WA |
to nsumner
iConnecthere:
After much experimenting with iConnectHere and Asterisk, I have found out the following:
g711 - US calls, good quality. g729a/gsm - international, at least to Ukraine. Quality is pretty horrid there. Looking for the VOIP provider that will allow g711 internationally. |
|
|
to wiggles4
Update for BroadVoice:
The currently have g.711u available on all proxy servers.
In addition g.726-32 and g.729a are available on the Chicago proxy. The intent is that both will become available on all proxies after testing is completed.
Please note: As of right now, no matter what codec you select for calls this will only change outgoing calls. When you get a call their servers are always going to lock on g.711u. In fact, when I made g.726-32 available as my only codec, inbound calls failed. |
|
kitonne join:2004-08-20 Highland Park, IL |
to wiggles4
Sipphone is currently using G711 and GSM on their PSTN gateway; 800 numbers gateway is using G711 only, afaik
nufone.net is using G711 and G729 - will take your preferred codec |
|
tj008 join:2004-06-24 Cincinnati, OH |
to wiggles4
Adding to the research...
Dialpad uses g723.1
|
|
vonsenJust Because Premium Member join:2005-01-06 |
to wiggles4
Skype codecSkype uses the iLBC codec. |
|
tj008 join:2004-06-24 Cincinnati, OH |
tj008
Member
2005-Jan-10 9:50 am
Re: Who uses what Codec?Clarification from different CS rep:
Dialpad uses g729a for line 1. Line 2 uses g723.1.
|
|
vonsenJust Because Premium Member join:2005-01-06 1 edit |
to wiggles4
Lingo firmware upgrade addes g726 codec to customers using the utstarcom adapter. Lingo uses g729 by default, also capable of negotiating g711 if remote end does not have g729. It's not clear if T38 has been implemented for faxing. edit: to clarify T38 status -- Email these Lingo executives about the misrepresented 18% hike: psingh@primustel.com,nhazard@primustel.com,tkloster@primustel.com,jdepodesta@primustel.com,t book@primustel.com,smcintyre@primustel.com,anayar@primustel.com,tlawson@primustel.com,mguirg is@primustel.com,jmelick@primustel.com,jrosenblatt@primustel.com,ghicks@primustel.com,mmagil l@primustel.com |
|
|
to nsumner
Just an FYI -
Vodavi in theirVoIP offerings use G.711 @ 110kbps for "full" B/W connections and G.723.1 @ 22kbps when B/W needs to be limited. G.723.1 can sound almost toll quality when you have some control over QOS.
Do you understand the deference between G.711u-law and G.711a-law? |
|