Snoop Posted March 28, 2013 Report Share Posted March 28, 2013 We are running the SNOM One VMware Appliance and are having problems with transcoding. Our gateway uses g.729, but with the SNOM one license model we are only able to run 10x concurrent calls. Our extensions therefore have to use other codecs. Internal calls are fine, but the moment we attempt calling through the gateway the calls are garbled and nobody can hear anything. Changing the extensions to g.729 solves the problem, but we are then limited to 10x concurrent calls both internally and externally. We are using SNOM One Blue 4.5.0.1075. Quote Link to comment Share on other sites More sharing options...
Vodia support Posted March 28, 2013 Report Share Posted March 28, 2013 Can your gateway run other codec, that would help some? The blue license has a set limit for only 10 g729 calls however version 5 lets you expand the numbers of concurrent calls on g729. http://snomone.com/alacarte Transcoding can also tax your CPU which is why you hear the garbled effect. Quote Link to comment Share on other sites More sharing options...
Vodia PBX Posted March 28, 2013 Report Share Posted March 28, 2013 Transcoding always reduces call quality. Don't try to mix other low-rate codecs like GSM or G726 in, this will result in even worse quality. VMware could be another risk factor. While it is possible to run the PBX in VMware glitch-free, AFAIK it requires some special resource assignments to make sure hat there is not another VM eating up CPU resources. When packets are garbled, it is very audible with G.729A while other codecs still sounds okay. Quote Link to comment Share on other sites More sharing options...
Snoop Posted March 29, 2013 Author Report Share Posted March 29, 2013 Thanks for the reply. 1. Our gateway provider only supports g.729, so we can't use any other codecs. 2. My problem with the transcoding is that it doesn't work at all. Irrespective of load on the PBX or VMware server. When I load Snom ONE on a Windows server guest on the same VMware host it works, so there is definitely a problem with the appliance. I have experienced this with multiple sites I manage, so I am confident that the appliance is the issue. Is there a fix for it? The problem with your 10 concurrent call limit and the inability to transcode means that all my calls (both internally and externally) are affected. If the transcoding can't be fixed I have to fork out for a Windows server license :-( Quote Link to comment Share on other sites More sharing options...
Vodia PBX Posted March 29, 2013 Report Share Posted March 29, 2013 Well... if your service provider supports only G.729A and you have only 10 G.729A licenses, then you can have only 10 calls. Workarounds with transcoding obviously causes significant challenges. That's why we added the a-la-cart item "calls" on V5. But it should make any difference if you are using VMware or Windows. If that is any difference, it must be caused by the performance of the system. Quote Link to comment Share on other sites More sharing options...
Snoop Posted March 30, 2013 Author Report Share Posted March 30, 2013 You misunderstand. The transcoding doesn't work at all when using the appliance. If I load a Windows server guest with Snom ONE on the same host the transcoding works. The problem with the 10 concurrent calls is that I have had to force my extensions to use g.729 as well in order to avoid the transcoding issue. I am therefore now limited to 10 concurrent internal calls as well. I can live with 10 concurrent trunk calls, because we only have 10 channels, but only having 10 concurrent internal calls is a massive problem. Quote Link to comment Share on other sites More sharing options...
Vodia PBX Posted March 30, 2013 Report Share Posted March 30, 2013 This is indeed weird. It should not make any difference if the OS is native or a guest OS (that's the point about virtualization). AFAIK the PBX code does not differentiate between the codecs by the OS. Are you sure the systems are otherwise the same? Quote Link to comment Share on other sites More sharing options...
Snoop Posted April 1, 2013 Author Report Share Posted April 1, 2013 I think the problem is with CentOS. I have tried installing Snom ONE on my own CentOS VM guest and had the same problem. I suspect a timing issue, which is quite common in virtualization. Windows seems to manages it better then Linux. Transcoding is obviously very dependent on accurate timing, so it would make sense if this was the case. Quote Link to comment Share on other sites More sharing options...
Snoop Posted April 3, 2013 Author Report Share Posted April 3, 2013 Is there any way to buy additional g.729 licenses for version 4? Quote Link to comment Share on other sites More sharing options...
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