Trouble Shooting Dlink Moca Speeds

[dbailey75]

Ok, I've had the MoCa's (Dlink DXN-221) up and running for about 4 months, and I've not been able to stream any bd files much higher than 15MB/s, so full bd's are a no go. I've finally gotten around to doing some trouble shooting, I've attached my Network diagram, I'm no artist, but you should get the idea.

Config one shows my setup and the PC and WHS speed files show's my speed results using Jperf from the HTPC connected to the Mocas. 23-28 Mbs, not what I was hoping, but explains my issue with BD files. So I replaced all the the spliters on the outside of the house with 2Gh's and I found one in wall filter in the house, replaced that one too, I have one 1gh out side that's grounded but is not in the moca loop, I'm going to replace it soon with a Point of Entry filter to help keep the moco signal in the house but this should not affect my speed. Ok, I was originally using the auto scan, and then tried other frequency's, my speed results where identical, no change at 1200, 1250, 1300, etc. I next checked for firmware updates, there was an update on Dlinks site, so I flashed each unit with moca version 1.1, no change, jperf results are the same.

So I did the 1m coax test shown in Config 2, I connented the Moca's together using a 1m long RG6 coax cable, I don't have the jperf results, but they were identical to what I posted for Config 1, reference the WHS and PC speed jpegs. So i'm scratching my head on this one, why am I only able to get 1/3 the speeds that I should be getting.

My tests have one thing in common, the router and 8port switch are still there, is it possible that one of these devices are causeing the issue? I don't have the jperf results saved, but looking af the config diragrams, my office PC to my WHS speed results where 125-160 Mbs for a single stream, that seems on par for a cat5e gb router/switch connection.

My router in the office is the Dlink Dir-655, the 8Port GB switch is a trendnet I believe, and the router/switch connected at the other end of the moca is a netgear running DDWrt in AP/swith mode with 10/100 ports.

I ran other tests removing the netgear router, and connect the PC directly to the moca adapter, and no change.

Any ideas? I was thinking about purchasing another set of the dlinks just to see if they would yeild the same results, is it possible my set may be defective.

My home was build in 1998, I think I have RG6, but it could be RG59, I can't find anything writen on the cable, but even if RG59, and refereceing my 1m test, should not have a impact on my speeds.

One thing that was odd was the fact that my PC has a slightly faster speed then my HP EX485, I was going to upgrade the Nic drivers on the whs, but since I don't have a kvm, I was afraid if something did not upgrade correctly, I'd be in trouble.

Edit: My Config one show's 4 connections on a 3 way splitter, opps, should be 3 TV's/outputs.

Also,I had the coax going through a surge protector before hitting the Moca adapters, I now have the moca's in from of the surge protector, still no change in throughput/speed
Thanks
Dan

 

[thiggins]

Reset the adapters to defaults and disconnect them from everything else. Then connect them back to back with a PC connected to each one and run your test.

I would use a timed big file transfer vs. iperf/jperf. There are too many settings to tweak and the defaults can give you misleading results.

 

[stevech]

Ok, I've had the MoCa's (Dlink DXN-221) up and running for about 4 months, and I've not been able to stream any bd files much higher than 15MB/s, so full bd's are a no go.

15MB/s... do you mean bytes/sec (capital B)? That would be 120Mbps, far faster than MoCA can do.

My D-Link MoCA yields about 70Mbps at the IP layer net of overhead. I think that's typical.

As to splitters, etc., a two way splitter has half the power per port. A four way splitter has 1/4th, etc. I'd think that MoCA could tolerate a reduction of 1/8th or maybe 1/16th as the sum of multiple splitters. Weak signal might cause a reduction in the modulation rate (bit rate), much as in 802.11 WiFi.

Simpler test than iPerf is freeware Qcheck. Or just transfer a 1GB file using a windows share.

My D-Link came with a setup program to see/change settings in the boxes, and see what frequency it's using. Also override the default frequency if there's a conflict with, say, a satellite feed via same coax. But I could not get that program to run on my PC, and D-Link tech support was not aware of the existence of the MoCA product. But I haven't needed it. To me, the MoCA boxes are dumb layer 2 devices much like an Ethernet switch. Install and forget.

 

[dbailey75]

15MB/s... do you mean bytes/sec (capital B)? That would be 120Mbps, far faster than MoCA can do.

My D-Link MoCA yields about 70Mbps at the IP layer net of overhead. I think that's typical.

As to splitters, etc., a two way splitter has half the power per port. A four way splitter has 1/4th, etc. I'd think that MoCA could tolerate a reduction of 1/8th or maybe 1/16th as the sum of multiple splitters. Weak signal might cause a reduction in the modulation rate (bit rate), much as in 802.11 WiFi.

Simpler test than iPerf is freeware Qcheck. Or just transfer a 1GB file using a windows share.

My D-Link came with a setup program to see/change settings in the boxes, and see what frequency it's using. Also override the default frequency if there's a conflict with, say, a satellite feed via same coax. But I could not get that program to run on my PC, and D-Link tech support was not aware of the existence of the MoCA product. But I haven't needed it. To me, the MoCA boxes are dumb layer 2 devices much like an Ethernet switch. Install and forget.

yes,that should be lower case b, 15Mb/s bit rate.

 

[dbailey75]

Reset the adapters to defaults and disconnect them from everything else. Then connect them back to back with a PC connected to each one and run your test.

I would use a timed big file transfer vs. iperf/jperf. There are too many settings to tweak and the defaults can give you misleading results.

Ok, I'll try a , Pc to PC connection, I assume I need to set each PC to a static IP, correct?

I've done the File tranfer test via windows, and i'm getting 10-11 MB/s.

 

[dbailey75]

Ok, I'll try a , Pc to PC connection, I assume I need to set each PC to a static IP, correct?

I've done the File tranfer test via windows, and i'm getting 10-11 MB/s.

Ok, I think I took the advice too literal, but I've connected one moca direclty to my router, dir-655 in the office, connected the other moca adapter using a 1m RG6 coax, and then pluged my PC directly in to the moca.

I completed a factory reset of each adapter, I'll need to do some reading on the Qcheck, believe I tried this once before but had some challeges getting it up and running.

Still unable to stream Highbit rate bd files. These things are pertty much plug and play, I'll admit my network skills are less than average, but other then setting of avsecurity password and changing the frequency there's not alot of settings to tweak.

Stevech, what should I be seeing with Qcheck? I'll read up on it later tonight, or tomorrow evening.

 

[stevech]

As said above, I believe that 70Mbps is what you can expect with MoCA.

You say "10-11 MB/s". If B is bytes, that means you somehow measured 80 to 88 megabits (Mbps) per sec which is more than I'd expect.

An HD stream shouldn't need half that.

Be sure your MoCA isn't using frequencies that conflict with a satellite receiver you have on your coax.

 

[dbailey75]

As said above, I believe that 70Mbps is what you can expect with MoCA.

You say "10-11 MB/s". If B is bytes, that means you somehow measured 80 to 88 megabits (Mbps) per sec which is more than I'd expect.

An HD stream shouldn't need half that.

Be sure your MoCA isn't using frequencies that conflict with a satellite receiver you have on your coax.

yeah, this is why I'm confused, the windows transfer numbers are just hair better than a 100Mbps, so this number has to be incorrect. I've not timed the actual down load, was hoping Jperf would provide an accurate result, but I'll give it another go with Qcheck.

I'm on cable, so no interferance, dlinks start at 950Ghz.

 

[dbailey75]

Qcheck Results

Ok, I just ran qcheck, i'm seeing throughput averging mid to high 50's Mbps, I have numbers as low as 42 and as high as 60. I just tested a 35mbps rate M2ts file on 4 different players, 3 of the 4 showed noticeable stuttering (XBMC, Boxee, VLC media player), sadly nero media hub played the file with only a 1 noticable stutter. could be a buffer issue with the players?

Note, the adpters are still connected with a 1m coax cable. Results with qcheck are much better then jperf, but I'm still not seeing 70 Mbps,but I should still be able to stream a 35Mbps HD file based on the results from Qcheck.

I'll do a few more tweaks to the hardware, and report back in a few days.

 

[stevech]

You have, of course, run those players connected directly to your cat5 LAN, no MoCA, no WiFi?

And they did not "stutter" (drop frames is what I call it).

Confirming: No satellite TV sharing same coax?

 

[dbailey75]

yes, the PC connected the moca adapter was my primary HTCP which had no issues connected to my gig switch, I've move it upstairs replacing an Ion PC that I eventually gave up on and sold on ebay, different story.

Ok, I've connected two PC's, not the HTPC mentioned above, but my office PC and My wifes laptop using only the moca adapter, 1m coax, cat5, and cat5 crossover, running qcheck, receive a consistent 65-66 Mbps.

So the adapters are checking out, close enough to the 70 Mbps.

update:I've connected everything back to my network, with the laptop connected via cat 5, moca adpater, 1m Coas, moca, and cat 5, to my router, and i'm getting the same consistent results of 65-66Mbps, I forgot to mention that I changed the file size in qcheck to 1000Kbps for all Qcheck test performed.

One more update, as i've read a bit more on SMB, the test above was on two vista machinces with SMB 2.0, the WHS is based on server 2003 and is SMB 1.0, and my HTPC's, are both running Windows 7, smb 2.1. I'll connnect it all back up and test streaming from my whs to the HPTC , and then stream the same file from the vista PC in my office , and then to my other windows 7 PC in the family rooom just to see if there are any differences.

I don't think I'll be able to do much more this week, but will try to pick up again on Friday or Saturday.

 

[Bob K]

Did you ever find a solution to your bandwidth problems?