Citrix XEN server

[SimonD]

Hi all,

I know this is a bit of a 'how long is a piece of string' type question but I was hoping to get some help here!

I'm trying (using the free download initially) to create a 3CX phone system running on the new Citrix Xen Server (a virtualisation platform similar to VMWare ESX). The server set up works fine as does installing the 3CX softphones. The system works except for the call quality which is exceptionally bad. At the moment I am just trying phone calls between 2 softphones running on Windows XP (the desktops are also running as virtual machines) and I have clear audio for a few seconds before it all breaks down. The audio breaks up and stutters badly and while it is possible to make out what the other person is saying it's not very easy. I'm pretty sure this isn't related to running everything on virtual machines per se though I realise it could be a contributing factor. The project I'm working on is such that I can't build the machines on separate physical servers to rule virtualisation out - virtualising it all is the whole point of the project! The audio on the XP desktops works fine in general it's just the VoIP traffic that is very bad. Are there any performance tools I can run or logs (aside from the logs I can see in the admin console) that I could check?

In addition I've not been able to find on the 3CX site any minimum specs for the server/softphone machines. I want to check this just to make sure I've not done something stupid (I may have missed them in which case I apologise). The joy of virtualisation is that I can add more memory etc. easily if I need to!

Thanks in advance for any help,
Simon

 

[sipero123]

Re: Poor call quality using 3CX softphones

Hi,

Cannot find the exact document but from memory I think it says something like Pentium 4 CPU, 1 Gb minimum ram, 2 Gb recommended.

I have several VMs running Hyper-V, XEN, and VMWARE and seems to work ok with 1 Gb albeit for my latest one I'm using 4 Gb ram.



Jonathan Hamon

 

[SimonD]

Re: Poor call quality using 3CX softphones

Matt, part of the project I'm working on is to virtualise this stuff so I'm sure we'll crack it...

I've 'played around' with the server and am now in the position whereby the call quality is a a lot better for quite a while but then fades on one extension after a minute or so. We think this could be due to a network issue so we're going to try some different servers tomorrow. If that doesn't work then I'm going to look at getting it to work on 'real' PCs to see if I get different results.

Simon

 

[sipero123]

Re: Poor call quality using 3CX softphones

Hi,

As far as how well this works in a virtualised environment very much depends on the spec of the host infrastructure. My latest Hyper-V VM is running on a host machine with 64 Gb ram, iSCSI SAN SAS storage with RAID 6 so perhaps does not compare with lesser VMs.

I think there are of course some disadvantages of a locally sited machine but this in my opinion needs to be balanced against other issues like under deployment of hardware, and the redundancy and support that a datacentre can provide.



Jonathan Hamon

 

[ciscotech2007]

Re: Poor call quality using 3CX softphones

Because your virtualizing your softphones even if you could prioritize the virtual OS and network data the HOST operating system will still get the most resources and highest priorty. Even with hyper v there are issues.

Although 3CX server can be virtualized, installing softphones on virtual machines are not recommended. Audio transcoding will be delayed.

realtime stateful communications require priorty in OS and network communications over stateless HTTP transactions.

 

[ciscotech2007]

Re: Poor call quality using 3CX softphones

And here's 3CX server requirements;

http://www.3cx.com/manual/3CXPhoneSystemManual7/phone-system15.html

 

[N_G]

Call Quality will be effected by network and server performance issues. We have never tested with Citrix XENserver, but know from tests that call quality will suffer a lot on an underpowered VM or wrongly configured VM....

 

[UnifiedVox]

3CX v7 worked great on Citrix Xen but when we upgraded to v8 any recorded message (Automated Attendant, Voice Mail Recordings, etc) was very choppy.
We had to downgrade to v7 until we can move it to its own dedicated box.