MoCA Coax-Ethernet Bridges - My Experience

[SteveW]

In case anyone is interested, I bought a set from Netgear - MCAB1001 is the product number you see on the Internet stores (although the box they were in says they are MCA1001). They are Coax to Ethernet bridges,

I am using them as a solution for our extender in our bedroom. Wiring RJ45 was going to be a major PITA.

I must say, after using them for a week, they have been flawless. I've been pumping 1080P Bluray rips and HD-PVR recordings through them without them even flinching. Stats on the bridges say I'm getting 254 Mbps, without a single error on the error counter (max speed according to Netgear is 270Mbps). I suspect if you had more then 2 on your infrastructure, you'd see a slight speed drop and a few errors, but still...

My infrastructure in my house is all for multiple Expressvu receivers, so all of my coax is RG-6 with snap-and-seal connectors.

I tried wireless G for the bedroom extender... had a lot of problems with drops and sync. The coax bridges have definitely solved my issues.

-Steve

[bcjenkins]

Price per pair is steep compared to the what nim-100s were selling for on ebay. Wonder how it compares to Actiontec's model?

http://www.provantage.com/actiontec-...2~7ACTI04X.htm

B

[evilpenguin]

Glad to hear its working well for you, I almost bought one of those today. My big concern is security as I live in a condo and I share coax with then entire building. Do these have some type of pairing/authentication method?

[bcjenkins]

I know the Moto ones do.

B

[SteveW]

Originally Posted by evilpenguin

Glad to hear its working well for you, I almost bought one of those today. My big concern is security as I live in a condo and I share coax with then entire building. Do these have some type of pairing/authentication method?

If I recall correctly (I'm at work) the encryption supported is DES. The key can be 12 to 17 characters long. Set all of yours on the same key, and you're set.

These are MoCA 1.1, so I believe you can have up to 16 of them sharing the same coax infrastructure.

Provantage had a good price on them (comparatively speaking), so I got mine there.

[fyodor]

FWIW, it's my understanding that the signals cannot go back through an amplifier-even those amplifiers that are two-way for cable modem purposes don't enable pass-back of the frequencies used by MoCA. So if you're concerned you can stick an amp at your cable drop.

F

[Sparhawk6]

Steve, thanks for your review of the MoCA adaptors.

I have a couple of questions: Do you use cable set top boxes and a cable internet modem along with your MoCA adaptors? Does that cause any interference?

[fyodor]

Originally Posted by Sparhawk6

Steve, thanks for your review of the MoCA adaptors.

I have a couple of questions: Do you use cable set top boxes and a cable internet modem along with your MoCA adaptors? Does that cause any interference?

I have a cable modem working with no interference. These are designed specifically to use different frequencies.

F

[Sparhawk6]

Originally Posted by fyodor

I have a cable modem working with no interference. These are designed specifically to use different frequencies.

F

Thanks Fyodor. What is your experience with the devices? Getting enough throughput to broadcast HD video without hiccups?

[SteveW]

Originally Posted by Sparhawk6

Steve, thanks for your review of the MoCA adapters.

I have a couple of questions: Do you use cable set top boxes and a cable internet modem along with your MoCA adaptors? Does that cause any interference?

The RG-6 I'm using was previously for my Bell ExpressVu (Dish) receivers. These bridges do NOT allow satellite over the same coax cable. They do however allow cable TV frequencies.

Basically my receivers are now with my Sage server on their own coax feeds, so not an issue for me.

Something to note: When I tested these coax bridges back in April when I got them, I had no problems with the extenders and bluray rips. Since I wasn't ready to go prime time with my sage server, I stored the bridges. Got them out for my final install about 3 weeks ago, and now noticed some stutter with Bluray rips. I backrev'd my extender back to 20090403 and it was practically no stutter. The stuttering seems to be introduced around the 20090616 firmware and after. I'm doing some testing to get to the bottom of it. It may be related to the bridges being set to scan and choose a frequency rather than locking them at a certain frequency. Interestingly enough around 20090616 is the same time I started having trouble with my extenders on cat5e stuttering in blurays. I worked with the Sage beta guys, and they were able to fix it in 20090702 for my extenders on cat5e. Note I have no problems with the latest firmware, and DVD or HDPVR recordings.

I'll post back here when I get to the bottom of it.

-S

[fyodor]

Originally Posted by Sparhawk6

Thanks Fyodor. What is your experience with the devices? Getting enough throughput to broadcast HD video without hiccups?

I've never had issues watching HD recordings stored over the network. However, these are Comcast downgraded HD recordings (10-12 megabits/s).

Blu-Ray can put a little more strain on the system with higher average bitrates and much higher peaks (I don't have any blu-ray rips).

In terms of transfer speeds, I haven't done elaborate testing. My downstairs computer gets about 40 mbit/s transfers from the upstairs NAS. Other upstairs locations (also connected via MoCA) get around 60-80 megabits/s. This could be an issue with the setup of the computer downstairs as much as anything else. It's been fast enough for me so I haven't tinkered with it.

I am using the NIM-100s (MoCA 1.0) which technically are a little bit slower than the new retail MoCA gear (but were much much cheaper).

F

[SteveW]

Originally Posted by SteveW

The RG-6 I'm using was previously for my Bell ExpressVu (Dish) receivers. These bridges do NOT allow satellite over the same coax cable. They do however allow cable TV frequencies.

Basically my receivers are now with my Sage server on their own coax feeds, so not an issue for me.

Something to note: When I tested these coax bridges back in April when I got them, I had no problems with the extenders and bluray rips. Since I wasn't ready to go prime time with my sage server, I stored the bridges. Got them out for my final install about 3 weeks ago, and now noticed some stutter with Bluray rips. I backrev'd my extender back to 20090403 and it was practically no stutter. The stuttering seems to be introduced around the 20090616 firmware and after. I'm doing some testing to get to the bottom of it. It may be related to the bridges being set to scan and choose a frequency rather than locking them at a certain frequency. Interestingly enough around 20090616 is the same time I started having trouble with my extenders on cat5e stuttering in blurays. I worked with the Sage beta guys, and they were able to fix it in 20090702 for my extenders on cat5e. Note I have no problems with the latest firmware, and DVD or HDPVR recordings.

I'll post back here when I get to the bottom of it.

-S

I'm happy to say my issues with my MoCA bridges is fixed thanks to help from Sage, and thru a little research. The latest firmware works flawlessly with the bridges.

Sage had me run iperf between the server and the HD200 on the other side of the bridges to see what performance I was getting.

Found that with a 32K buffer size, the server -> HD200 setup seemed to lose throughput every few seconds. Even though reviews of the bridges say max thruput RJ45 to RJ45 on the bridges was about 70 Mbps, the HD200 would max at 40 or 50 Mbps, but dip at times to 10 Mbps, messing up bluray playback. I did not see these same dips to the same level when connecting my laptop to the bridges and the server with iperf. It seemed to be affecting the HD200 more.

I found running a buffer of 128K in iperf kept almost flawless throughput over the bridges and the HD200. Checked my Sage.Properties file on my server and found that the "miniplayer/forced_max_push_size=" was set to 32768 (32K). Changed it to 0 to allow up to a max of 128K. This instantly allowed my 99% of my Blurays to play properly with no stutter on the HD200 connected to the bridges.

I had 1 Bluray that would still sometimes stutter the odd time during scenes with fast paced scenery changes (Quantum of Solace). I saw references in the last few firmware releases for the HD200s regarding TCP windowing, so did some research.

Found an article on the internet regarding TCP Window scaling and TCP Receive Window Size, and a utility to change them to improve performance. Checked my server, and indeed TCP Window scaling was turned off (XP SP3). Used the utility to turn on scaling and change the maximum receive size on my Sage server.

Tried it again, and poof! Everything is working perfectly. As a matter of fact, testing of the throughput to the HD200 from the server over the bridges now shows that I'm getting up to 90 Mbps over the bridges - higher than even the internet reviewers of the Netgear MoCA bridges were getting in their initial testing.

So, my issues with the bridges have been solved. I can highly recommend using these bridges for the HD200s - IF - you have a good coax connection, and are willing to do some tweaking on your Sage server's TCP settings.



-S

[hingepin]

I've encountered a possible issue of interference with my actiontec bridges and comcast's digital voice. Anyone experienced this? Is there a way to fix it?

[mattdcknsn]

Thanks Steve, I am running the actiontec MOCA bridges and am always wanting to improve performance. Thanks for the information.

[chrisc983]

Originally Posted by SteveW

Found an article on the internet regarding TCP Window scaling and TCP Receive Window Size, and a utility to change them to improve performance. Checked my server, and indeed TCP Window scaling was turned off (XP SP3). Used the utility to turn on scaling and change the maximum receive size on my Sage server.

-S

By any chance do you have the web site for that article? I'm not sure if it would apply to WHS but its worth checking.

[Sparhawk6]

I thought I'd add my own quick review here of the Netgear Moca device.

These things are simple to install. I plugged them both in, connected the coax, and in about 30 seconds I had a connection.

I quickly ran an independent LAN speed test. I got about 72 megabits per second. I have not yet tried the device's own speed test.

My HD200 is connected in the TV room next to the office where the comcast net connection comes in. I estimate that the length of coax line is about 40 feet. My cable line is split about 6 or 7 times in the office.

I am getting flawless HD playback on the HD200. Videos play without issue. I cannot tell the difference between using the ethernet connection and using this device.

I am very happy with this device. Anyone who has a coax line to the TV but no ethernet line should seriously consider these devices.

The price is the only issue I have with this device - $200 for a pair. I thought about bringing an electrician out to the house to get an estimate for laying cat 5e cable to 4 different locations in the house. If it was less than $400, it would have been worth it to do that instead of buying these device (since I will need another pair for my two other rooms). But I decided to forget the hassle of trying to pull through closed walls.

[Chriscic]

It cost me $1000 to run ethernet to four rooms in my house. But, that was from the basement to the second floor. If Moca was an option when I did it, I probably would have tried that instead. Powerline was a total failure.

It is nice to have the gigabit speeds though for future-proofing I guess.

[hingepin]

I did run itno an issue when I installed FIOS a couple months ago. I had issues with the guide not showing up on the cable box closest to the adapter. Bleed over? Some of the line is the old RG59. Some of the run is new RG6. Haven't tried it on the all RG6 yet, which would be to a PS3 anyway.

[SteveW]

Just wanted to follow up....

I started to run into a problem with certain Blurays last fall and this spring while playing them on my extender that is using the Netgear MoCA bridges.

Would get severe stutter on movies such as Avatar, Quantum of Solace, and a few others, but not on others. DVDs were no problem, and HD-PVR recordings were not problems. Seemed like it was a bitrate issue on some Blurays.

The fine beta folks at Sage tried to help me with it. Tried some beta extender firmwares, which addressed some issues they were seeing in my Wireshark logs, even though I was able to get a consistent 89-91 Mb/s throughput between the extender/MoCA bridge and my Sage server as shown by Sage having me run IPerf / JPerf.

Well, I finally took some time to try to get to the bottom of this once and for all last weekend.

In my house, I have two switches. I have a HP Procurve 1800-8G gigabit switch in the basement near my Sage server that serves the basement and first floor, and a HP Procurve 1810-8G gigabit switch that serves the second floor.

Through a combination of long RG-6 and CAT5e patches, turning flow control on and off on the switches, locking port speeds, etc, I found my stuttering problem with MoCA on my bedroom HD-200 was being caused by the 1800 switch itself. When I swapped the locations of the 1800 and 1810, my stuttering problems disappeared.

I was somewhat shocked at this since my assumption was that it was a problem with the coax run. There's no update firmware for the Netgear MoCAs. I updated the 1800 switch but it made no difference.

Why there is some sort of incompatibility with my MoCA bridges and one of my two HP gigabit switches I don't know. They are configured the same, and are practically identical - the only difference is the 1810 is the newer version of the 1800.

For comparison purposes, I tried a short stint with my MoCA bridges plugged in to my Linksys 610N router (at gigabit). While I would see the odd stutter every few minutes while plugged into the Linksys, it was no where near as bad as being plugged into the 1800 switch, but not as clean as being plugged into the 1810 switch.

Thought I would put this out there FYI for anyone going MoCA (at least Netgear's) that if you are having issues, don't necessarily blame your coax... Do some trial and error, and don't assume that it's not an issue somewhere else on your network.

Hope this helps.

- Steve

[stevech]

I've been using a D-Link (not my preferred brand) MoCA.
Works great. Love these layer 2 bridges. No management/rebooting.
I'm just doing 100BT