MVP and Powerline Networking: Incompatible?

[mdnttoker]

I downloaded Qcheck and tested the connection between my MVP and Server in 2 different ways. (The MVP is connected to a switch port on my Linksys WRT54GL running DD-WRT firmware).

1) Linksys WRT54GL configured as a wireless bridge: GB-PVR loads just fine and video stutters every once in a while when there is interference. Qcheck notes ~5% UDP streaming packet loss between WRT router and the gb-pvr server.

2) Linksys WRT54GL connected to Netgear HDX101 powerline routers: GB-PVR rarely loads - and sometimes MVP "can't find a server". But in this configuration, Qcheck notes 0% UDP streaming packet loss between WRT router and the gb-pvr server.

What does the 0% UDP packet loss tell me? Would a duplex mis-match cause UDP packet loss?

Thanks,
Dan

[Kristan]

(long rant/post warning!)

I'm having the same problem, but with a nortel baystack 450-24T switch.

Quick summary of my network:

ADSL modem->smoothwall firewall->8 port cheap netgear switch in the study, main PC hangs off this, then a cable to the loft to the baystack (in the loft - too noisy to have anywhere else!) which then runs to the bedroom (MVP), lounge (xbox 360), spare room and 54g wireless bridge.


When I first connected the MVP up I could not get it to boot up at all. Having recently cabled everything I assumed it was my dodgy wiring and started crimping new ends everywhere. However after much frustration and cable cutting I connected my laptop to the same cable and it came up fine! Now suspecting the switch, I ran a long cable from the netgear to the MVP and it booted fine. So:
netgear->mvp fine
baystack->laptop fine
baystack->mvp not fine

I was totally at a loss, in the end I was fidding with the port settings on the baystack and noticed it had autodetected 100mbs/half duplex. So instead of letting the port autodetect, I forced it to 100mbs/half duplex, cycled the MVP and it fired up! Video stutters though and the connection drops off, so I'm still not totally sorted.

Took the mvp off (until it works my girlfriend would like to be watch stuff, so the original xbox and XBMC [which has always worked flawlessly btw] went back on) and at first, that wouldn't play either. Went back into the switch, reset the port back to auto detect and hey presto, working again.

So in conclusion, it looks like csy is dead right! Some switches and the MVP won't play nice together. Out of interest, what revision is your MVP? I have an H3, just wondering if they've changed something recently. I had assumed that the MVP could only do half duplex after seeing that's what the switch detected, so I'll try forcing it to 100/full tonight and see if that helps.

[Kristan]

There is no easy work-around to your problem. Another user purchased a configurable Ethernet switch and connected the MVP directly to it and configured the switch port facing the MVP to 100/half. Another alternative is to find a cheap unmanaged switch that can detect the very short link-down interval and does correctly re-negotiate 100/full with the MVP, and insert that inline between the MVP and the Powerline adapter.

Just thinking about this actually, after loading the dongle.bin, would pulling and re-inserting the network cable not do the trick? The switch and MVP would notice the link going down, renegotiate and should come back up ok? I guess timing might be rather crucial!

[csy]

Just thinking about this actually, after loading the dongle.bin, would pulling and re-inserting the network cable not do the trick? The switch and MVP would notice the link going down, renegotiate and should come back up ok? I guess timing might be rather crucial!

I agree - that should work, but timing may be important (as you mentioned).

[csy]

so I'll try forcing it to 100/full tonight and see if that helps.

It will not work to force one end to 100/full and leave the link partner auto-negotiating because the forced port will not advertise its capabilities to the auto-negotiating link partner, and the auto-negotiating partner will fall-back to half-duplex, hence duplex mismatch.

[Kristan]

It will not work to force one end to 100/full <snip>

good point! Had I thought about the fact that I had to force it to 100/half to get it to work I may have figured that out in the end Unless there's a way to force the MVP ethernet port to 100/full also.. I don't really know enough about the internal workings of the MVP or linux kernel to do that though!

[mvallevand]

I had assumed that the MVP could only do half duplex after seeing that's what the switch detected, so I'll try forcing it to 100/full tonight and see if that helps.

Actually this is a good question about the various dongles out there. Do any or all of them support full-duplex operation? For some reason the Hauppauge provided software that the mvpmc project uses defaults to half-duplex after the bootloader connects at full duplex and I wonder is the same is true for other dongles, or gvmvp.bin? This transmission change does mean that some hubs and switches will experience problems and probably more importantly, collisions while using gb-pvr and the mvp are inevitable.

For mvpmc there is a work around and I might even try full-duplex as a default if I determine that Hauppauge has turned it on.

Martin

[Kristan]

After a bit of testing, I concluded that the only way to get a reliable connection was to force the port on the switch to half. All of my testing was with hauppuge dongles, though. Have you seen mii-tool? I was thinking of trying to build my own mvpmc image with that on to try to force 100/full after boot, but without knowing what chipset is on the MVP I didn't fancy my chances of getting it to work.

[mdnttoker]

Just as a final follow-up, as suggested once elsewhere in this forum, I was able to get the HDX101 powerline routers to work fine with the MVP once I put a DELL 8-port switch in between the MVP and the powerline routers.

http://www.dell.com/content/products/pro...=bsd&cs=04

Still bothers me that it took another $80 high-performance switch to get this setup to work.

You would think that the MVP + Powerline networking would be a natural combination given that most residences aren't wired w/Ethernet.

And just to let everyone know, even with the A/C, microwave, and cordless phones on, I get a minimum of about 20mbps from one end of the house to another with these routers.

Plenty for std. definition TV.

-Dan

[dfdario]

Just back from my holidays I red your post.

I experienced the same problem in the past when my modem-router was in the off state.

After a few tests I assumed that:

• if MVP is power cycled it has to load the dongle.bin from GBPVR hence it needs the router to get a valid IP via DHCP.
  
• if MVP is started from sleep mode the modem router has no effect in the connection because of MVP already has a valid IP.