Meaning of packet loss statistics

Reception, channel detection, network issues, CableCARD setup, etc.
Post Reply
retate
Posts: 17
Joined: Mon Nov 23, 2009 8:11 pm

Meaning of packet loss statistics

Post by retate »

When running the low level test for network packet loss there are four types of errors reported for example.

2224397 packets received, 3002 overflow errors, 8 network errors, 0 transport errors, 0 sequence errors

I have looked in the troubleshooting material, but I cannot find definitions for these errors. I can guess at what they mean, but that is not a good way to troubleshoot. Some questions that come to mind.

Are sequence errors missing packet(s), out of order packets, or both?
Overflow errors in my experience would mean that packets are being discarded due to typically insufficient buffering, but this could be at a hardware chip level or at a software level. What conditions are being counted as overflow errors?
Are network errors packets with CRC errors, what other types of packet errors are included in this statistic?
What conditions will count as transport errors?

information on the conditions that can cause these errors would be very helpful for those of us who would like to troubleshoot/improve their network.

nickk
Silicondust
Posts: 15845
Joined: Tue Jan 13, 2004 9:39 am

Re: Meaning of packet loss statistics

Post by nickk »

Overflow errors mean your receiving PC/device isn't keeping up... data is being received but not consumed fast enough.

What type of PC/device are you running the test on?

Nick

retate
Posts: 17
Joined: Mon Nov 23, 2009 8:11 pm

Re: Meaning of packet loss statistics

Post by retate »

The test was being run from a system running Server 2019 (I7-5960X (8 processors), 32 GB memory, Samsung 970 M.2 drives, HGST 12 TB & 14 TB hard drives, 10 Gb ethernet card). This system is where I am running HDHomerun DVR software recording from a Prime (mostly) and a Connect Quarto. The system and network should be over provisioned for everything being done. I am seeing some intermittent problems with HDHomerun recording which I suspect are network related which is why I was testing. Since my original post I have done a few additional tests which have not shown overruns, but are showing N errors. I plan to do more testing to try to isolate where the problem is.

nickk
Silicondust
Posts: 15845
Joined: Tue Jan 13, 2004 9:39 am

Re: Meaning of packet loss statistics

Post by nickk »

Try running two packet loss tests at the same time using different tuners on the same HDHomeRun - that will double the amount of data being transferred... see if the network loss goes away.

If it does (higher data rate = no loss) then it points to an Interrupt Mitigation / Interrupt Moderation problem which can likely be addressed by change the NIC configuration on the server.

Nick

jseymour
Posts: 431
Joined: Sat May 12, 2018 8:46 am

Re: Meaning of packet loss statistics

Post by jseymour »

retate wrote:
Sat Apr 25, 2020 10:29 pm
The test was being run from a system running Server 2019 ...
Color me confused. A network bandwidth/performance test requires two cooperating network nodes. His MS-Windows Server was one. What was the other, and what test is he running?

rpcameron
Posts: 922
Joined: Fri Mar 25, 2016 9:55 am

Re: Meaning of packet loss statistics

Post by rpcameron »

jseymour wrote:
Sun Apr 26, 2020 7:48 am
retate wrote:
Sat Apr 25, 2020 10:29 pm
The test was being run from a system running Server 2019 ...
Color me confused. A network bandwidth/performance test requires two cooperating network nodes. His MS-Windows Server was one. What was the other, and what test is he running?
From the first response, looks like it was something like

Code: Select all

hdhomerun_config FFFFFFFF set /tuner0/vchannel 2.1
hdhomerun_config FFFFFFFF save /tuner0 /dev/null
and the other node would be the tuner.

jseymour
Posts: 431
Joined: Sat May 12, 2018 8:46 am

Re: Meaning of packet loss statistics

Post by jseymour »

Ah. Got it. Never really looked into that. Thanks!

Post Reply