Network throughput is not consistent. Its choppy.

[giganto53]

Hey Guys,

I built a little Mini ITX tower and have been running Plex on it for a while and its been running fine. I just installed PeakHour4 on my Mac Mini to monitor network usage on my network and noticed something odd on my FreeNAS box. My network throughput seems to be choppy. it will jump from 200+ Mb/s to 0 then back to 200+. its not the program because I am monitoring other systems and the throughput is smooth.

I took a snip of the 2 graphs. the bottom is an AirPort express and the top in the FreeNas box. I was transferring video to it at the time. This also happens when streaming video using Plex

Any thoughts?

 

[kdragon75]

How did you transfer the video? Was this during playback?

 

[giganto53]

How did you transfer the video? Was this during playback?

I transfer via a SMB Share. And this happens during video playback and transfer.

 

[c32767a]

I transfer via a SMB Share. And this happens during video playback and transfer.

I'm curious how often your monitoring tool polls for data. once per second?

Counter data is updated asynchronously and sometimes the refresh rates of the various counters can combine to produce the kind of spikes you see. For example, the SNMP variables may only be updated every 3 seconds, but if you poll every 1, it will appear as if there is no traffic.

Code:

dalton:~ root$ snmpwalk -v2c -c public nas1 IF-MIB::ifOutUcastPkts.1
IF-MIB::ifOutUcastPkts.1 = Counter32: 2883446384
dalton:~ root$ snmpwalk -v2c -c public nas1 IF-MIB::ifOutUcastPkts.1
IF-MIB::ifOutUcastPkts.1 = Counter32: 2883447027
dalton:~ root$ snmpwalk -v2c -c public nas1 IF-MIB::ifOutUcastPkts.1
IF-MIB::ifOutUcastPkts.1 = Counter32: 2883447027
dalton:~ root$ snmpwalk -v2c -c public nas1 IF-MIB::ifOutUcastPkts.1
IF-MIB::ifOutUcastPkts.1 = Counter32: 2883447027
dalton:~ root$ snmpwalk -v2c -c public nas1 IF-MIB::ifOutUcastPkts.1
IF-MIB::ifOutUcastPkts.1 = Counter32: 2883447418

I was able run those about 1.5 seconds apart.. see how the 3 in the middle returned the same number, even though the NAS is loaded and passing traffic during that time.