So, in a few other post threads I've alluded to an issue I've had with streaming Recorded TV and Movies from my WHSv1 to my HTPC. The issue is 'stuttering' or 'jerkiness'; very brief hiccups in the stream, at least with Recorded TV. They weren't enough to really interfere with enjoying the show, but they were noticeable.
When I tried to stream a BD mt2s file today it was unwatchable; even the audio was totally broken up. Using 2011 made little, if any, difference.
Today was the day to tackle the issue head on. There are a lot of variables. Is it:
- something with my HTPC's ability to render
- something with my Atom 230-based WHS
- something with my network
I copied a BD file to the HTPC and played it. Again, perfect. OK then, it is NOT the HTPC. On to step 2.
Since there isn't a whole lot I can do with the WHS, I tackled the network next. The first test was to directly connect the WHS to the HTPC. I had to crimp a new cable cause the WHS is on the 2nd floor and the HTPC is on the main floor and I didn't have a long enough cable at hand. I have the proper tools and supplies, so no problem. I even have a PentaScanner to test the finished cable (which passed).
I played the same 2 files that had worked perfectly from the HTPC, but from the WHS this time. I got the same levels of stuttering as I'd had when the WHS and HTPC were not directly connected. So, it doesn't really look like it's the ethernet switches or cabling.
To test if it IS the WHS, I copied the 2 test files to my Win7 desktop computer and tried playing them. Again, I got the same levels of stuttering. I got the same results whether the Win7 computer was connected directly to the HTPC or via the LAN.
All 3 computers are using Realtek NICs. I'm not necessarily the biggest fan of Realtek but, I have to admit, for the most part they seem to work fine. To bolster this, I recalled that I hadn't really had any issue copying the test files around the LAN.
Alright, it seems not to be the HTPC, or the WHS, or the network hardware. What's left?
At this point I'm thinking settings, specifically network settings. I connected the Win7 computer directly to the HTPC again. To test connectivity, I started each computer continuously PINGing the other..I then started changing the settings of the NICs. Nothing really made much difference until I hit the Jumbo Frames option. On both computers it was disabled. I changed it to 9k packets. There was a brief interruption in the PING responses, then they picked up again.
I killed both PING sessions and played the Recorded TV test file. Perfect!. No stuttering, no jerkiness, audio is great. I stopped it and tried the BD file. Again, perfect! It started right up and played smooth as silk.
I connected the Win7 and HTPC computers back up to the LAN and tried playing the files. Again, both were perfect.
I changed the WHS NIC to use 9K Jumbo Frames and tried playing the files from the WHS. Again, perfect. Issue resolved it appears.
One thing I always try to do when troubleshooting is go back and try to replicate the problem, to prove what I did was actually the fix. I changed the HTPC to disable Jumbo Frames. Sure enough, the stuttering came back, just like before. I re-enabled 9K Jumbo Frames. Oh no! It didn't fix the problem - the stuttering was still there.
I RDP'd into the WHS to check it's settings. Sure enough, they were still set to 9K Jumbo. Ah crap; now what's the problem? Just as a test, I set the WHS to use 1514 byte packets, since it doesn't offer an option to disable, and OK'd my way back to the desktop. Then I went back and re-enabled 9K Jumbo Frames and OK'd back to the desktop again.
Voila! The stuttering was gone again. It appears that the WHS negotiated down to 1514 byte packets after I changed the HTPC but didn't auto-negotiate back up again after I re-enabled 9K packets. Something to keep in the back of my mind.
So the issue is resolved; it's been a good Saturday.
As you can imagine, the WAF is huge!
Apparently, size DOES matter.
I'm sure Jumbo Frames have been mentioned in other threads, no doubt by pcdoc/nocontrol. But, I'm not sure the subject has been the central focus of any thread, so I thought it deserved to be.