Is there a way I can change the tx ring size / txqueuelen on the physical nics and/or the vswitches of a vsphere host? I believe we are suffering from bufferbloat issues which is affecting our VOIP solution.
We have an Asterisk PBX and a checkpoint firewall running on the same vsphere host, with the firewall providing the internet connection via an ADSL connection. When the link gets contended, our VOIP call quality deteriorates to the point of being unusable. A simple test with mtr shows that under these conditions, there is 200-400ms latency added between the packets reaching the firewall and the next hop. When the link is not contended the latency is more like 5ms.
Prior to moving to this VMware solution, the firewall and PBX existed as discreet physical servers, and we never had this issue. We have concluded that the issue is likely to be caused by excessively long interface buffers on the vmware server (we have tried tuning the interfaces on the firewall VM to no effect), however, I cannot find a way to even display the tx ringsize / txqueuelen from the vmware host, let alone configure it. The esxcli command does not provide any info on this parameter, and ethtool -g/G reports "operation not supported". I have not been able to find any options in the vsphere client either. Is there any way this setting can be configured?
Thanks
