I’ve been battling an issue on a production machine for two weeks now that just will not let up. The core of the issue is that any network traffic to my FreePBX host intermittently has much higher response time than expected, from a typical 3-12 ms, depending where I’m pinging from, to 200-500 ms. I’ve noted this behavior in both SIP packets and ICMP ping requests to the FreePBX.
This behavior is not exhibited when pinging from the FreePBX to another host, nor are there any other network issues between hosts on the same network, even in the same physical machine. For comparison, the highest ping from my typical test machine to a host on the same physical server and network averaged 3 ms, with a jitter of 0.4 ms, while pings to the FreePBX averaged 11 ms, with a jitter of 53 ms!
While doing research, I ran across the dahdi_test command, which showed that my accuracy sporadically dips very low, to 70%, but unless I am mistaken, I am not utilizing any dahdi devices or interfaces, only pjsip, so I wrote this off as a symptom, rather than an issue cause.
Here are the machine details:
- KVM Virtual machine, 6 cores, 8 GB RAM
- Started on FreePBX 10.13.66, upgraded to SNG7
- Linux 3.10.0-693.5.2.el7.x86_64
Things I’ve done to try and remedy the issue, to no effect:
- Increased server resources
- Changed the network interface type, utilizing new driver
- Updated from FreePBX 10.13.66 to SNG7
What has me particularly stumped is why the ping command shows the same jitter, but the issue is only effecting this one machine. Anytime I’ve seen issues like this, they are network dependent, and some fix must be applied to the network configuration to resolve them, but this issue seems to be within the server itself.
I am at my wits end!
If there is any information that I can provide, or tests I can run that would be of service, I’d be happy to do so!
Help me FreePBX Community, you are my only hope!