[mythtv-users] Nvidia ION unreliable HDHR Prime at gigabit speeds

[Stuart Auchterlonie]

On 03/03/16 10:25, Anthony Giggins wrote:
> 
> 
> On 3 March 2016 at 07:59, Will Dormann <wdormann at gmail.com
> <mailto:wdormann at gmail.com>> wrote:
> 
> 
>         are you seeing dropped packets though?
> 
> 
>     Yes. That was the whole point of this thread.  Really only
>     noticeable with the HDHR at gigabit speeds though, due to no
>     retransmission and UDP. 
> 
> 
> I've made some changes which appear on the surface to have improved things
> 
> I've disabled ipv6 on both my frontend & backend (Backend previously was
> disabled but was re-enabled after I recently upgraded to 14.04)
> and I've enabled jumbo packets on both the frontend and backend (once
> again this was previously enabled prior to the upgrade but appears
> Network Manger does not honour this anymore)
> however on the ION frontend (zbox-id31dvd-plus) the max jumbo frames
> supported is 7000 however the backend is set to 9000 (really they should
> be the same) and your switch should also support and/or be configured
> for jumbo frames. 
> 
> I seem to no longer get a long delay when starting playback and even
> launching recordings and videos seems alot quicker.
> 
> I'll need to monitor over time though for dropped packets however since
> enabling dropped packets has only increased by 11 during 1.5GB of RX
> transfers.
> 
> $ ifconfig eth0 | grep "RX packets"
>           RX packets:31758537 errors:0 dropped:21144 overruns:0 frame:0
> 
> the previous 21133 dropped packets was over 41.7GB of RX transfers
> 
> Cheers,
> 
> Anthony
> 

I'd also take a look at the tcp / gro offload settings and try turning
them off to improve reliability. Sometimes if the hardware isn't quite
right, it's better to let the kernel handle that, than offload it to
the hardware.

Regards
Stuart