dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
1120
share rss forum feed

jsmiddleton4

join:2003-11-13
Glendale, AZ

[AZ] Amp vs no Amp readings


NO AMP

AMP
Having some stalls again here in Glendale. Had been trouble free for many months.

Moved to work at home and have business line from Cox along with my home line.

Share same feed as it is residential and there aren't two drops to every home.

Business install tech put amp back on my system even it was removed months ago and was in fact not needed.

Was fine for a few weeks but last week started with the stalls again.

So I captured readings with and without amp.

SNR doesn't seem to really improve all that much, same with upstream power level.

Channel level signal of course quite different but without the amp those are still in what I understand is acceptable range. Could be wrong but what I've found is the -6 level is ok.

Ideas?


Anonguy

@cox.net

You definitely do NOT teed the amp with those levels. -6 is fine!


jsmiddleton4

join:2003-11-13
Glendale, AZ

I'm thinking not as well. One of our forum friendly Cox guys is on it as well. Will be back with him on Monday.

If I understand what I'm seeing correctly, again IF, the problem is the SNR readings. Dropping below 40 not so good.

If....


Hoss
Sauters A Walrus

join:2000-10-05
Tulsa, OK

said by jsmiddleton4:

I'm thinking not as well. One of our forum friendly Cox guys is on it as well. Will be back with him on Monday.

If I understand what I'm seeing correctly, again IF, the problem is the SNR readings. Dropping below 40 not so good.

If....

What?

40 is a GREAT SNR (I get it consistently), but anything above 36, especially when channel bonding, is within spec.

jsmiddleton4

join:2003-11-13
Glendale, AZ

I did say If Hoss.

I'm passing along what the tech told me. The amp was needed due to the SNR.

He wanted it at 40 or above that when in the readings get down in the 30's its problematic.

But even at that with the amp the SNR numbers don't change all that much.

I of course do not know what his testing equipment showed.


jsmiddleton4

join:2003-11-13
Glendale, AZ
reply to Hoss

This from the FAQ here.

DOCSIS 3.0 modems:

Downstream power level (Receive): -15dbmV to +15dbmV
A value of -10 or worse indicates a poor downstream signal path. A tech would aim for a value close to the optimal 0 dBmV, but a good cable modem should be capable of working within the broader range of -10 to +10 dBmV, provided the downstream Signal to Noise Ratio remains good enough. Additionally all downstream channels should be within a +/-2db window with respect to each other.

Upstream (Transmit): 40-52 dBmV. A value within the range +40 to +52 dBmV is within spec with the low to mid 40's the most common. If the cable modem is going offline, and the upstream signal strength is at or above +52dBmV, then a poor upstream path is probably the problem.

Carrier/Noise Ratio: 35 db and above The downstream Signal to Noise Ratio must be 35 dB or higher on each channel. The lower ratio the more noise and the poorer the performance. The Cable Modem will have to keep requesting retransmissions of packets with uncorrectable errors.


Hoss
Sauters A Walrus

join:2000-10-05
Tulsa, OK
reply to jsmiddleton4

said by jsmiddleton4:

I did say If Hoss.

I'm passing along what the tech told me. The amp was needed due to the SNR.

He wanted it at 40 or above that when in the readings get down in the 30's its problematic.

But even at that with the amp the SNR numbers don't change all that much.

I of course do not know what his testing equipment showed.

The last tech I spoke with last year told me that 40s usually only occur when the line condition is a 10. Not common. My line condition: a 10. I suspect yours is, or is close. My power levels on the DS are typically about -2.

jsmiddleton4

join:2003-11-13
Glendale, AZ

1 edit

The tech was a residential install guy. It was the install for the business side for work at home.

I don't know if the business side for stability reasons has a higher bar?

10 being good like the movie Ten? Not sure what 10 means as these figures are all ratios correct? So is 10 some quotient factor or just a descriptor?

Edit: Sorry, tech was NOT a residential install guy. Left the "not" out.


jsmiddleton4

join:2003-11-13
Glendale, AZ
reply to jsmiddleton4

Changed ends, there's only a couple as the feed to the modem is just one split. One side goes to TV, one to modem.

Put in new 2.4ghz low loss splitters, not Monsters but not cheap ones either.

No amp.

Spent most of day setting up new Asus RT-N66U.

Very nice router.


digiblur
Premium
join:2002-06-03
Louisiana
reply to jsmiddleton4

Shows you those crazy spec'd splitters are really just a bunch of hoopla. I would go no amp too. It's always been my practice to never put a modem behind an amp. I saw a phone MTA behind an amp one time. Really?! What's the point of the battery then? No power = un-powered amp = drag the signal down to nothing.

Yes, the 66U is a very nice router. Especially after putting Shibby's Tomato build on it. Awesome features. I even put a spare 4gb micro-sd card inside the unit. Pretty cool!


lilstone87

join:2009-04-09
Portsmouth, VA
kudos:3
Reviews:
·Cox HSI

If you use the default N66U firmware, I suggest running RMerlin's custom build's which are based off of Asus firmware, with added fixes he has done. There are a couple fixes included in the asus firmware's from RMerlin, just to show he is good at fixing stuff in his own build's.

Also I have run Shibby's tomato firmware, it works very well, and has a lot more features. There is only one thing I don't like with Shibby's firmware, and that having a USB HDD connected to the router transferring stuff to it. As with the tomato firmware, you can only transfer at about 3MB's, with the Asus firmware that will go up to about 12-13MB's. So if you want to use a USB HDD connected to the router, and transfer data to it at a decent speed, I suggest running RMerlin's firmware for the N66U. The work around if you want to run Tomato will be simply disconnecting the USB from the router, and connecting to the source you want to transfer the data from. BTW this is based off of using a USB HDD formatted with NTFS.


jsmiddleton4

join:2003-11-13
Glendale, AZ

Thanks for the suggestion.

Loaded Merlin's last night. I like it. And he is adding features.

I was around the early days of the first "Tomato" and Linksys 54's and Buffalo's. I watched it grow. Same with DD-WRT too. It started out fairly small.

How Tomato began, Merlin's project has almost exactly the same feel to it.

No it isn't exactly the same. Tomato was and is stand alone and isn't plugging holes and adding features to the default firmware. I get it.

But the feel is about the same none-the-less.

I'll probably sticking with Merlin's and making a contribution.

Back to the thread......

My business connection worked just fine yesterday. I can't grab the status page off the 6180 its using. It is a business line with full blown IT support, lock people out of admin functions, etc., setup. I can't get to the 6180's status page with the usual IP address. I'm not going to try anything more than that. Last thing I need is to get in hot water over banging on network stuff that is clearly off limits to system users and reserved for the IT support guys.



digiblur
Premium
join:2002-06-03
Louisiana
reply to lilstone87

said by lilstone87:

If you use the default N66U firmware, I suggest running RMerlin's custom build's which are based off of Asus firmware, with added fixes he has done. There are a couple fixes included in the asus firmware's from RMerlin, just to show he is good at fixing stuff in his own build's.

Also I have run Shibby's tomato firmware, it works very well, and has a lot more features. There is only one thing I don't like with Shibby's firmware, and that having a USB HDD connected to the router transferring stuff to it. As with the tomato firmware, you can only transfer at about 3MB's, with the Asus firmware that will go up to about 12-13MB's. So if you want to use a USB HDD connected to the router, and transfer data to it at a decent speed, I suggest running RMerlin's firmware for the N66U. The work around if you want to run Tomato will be simply disconnecting the USB from the router, and connecting to the source you want to transfer the data from. BTW this is based off of using a USB HDD formatted with NTFS.

I had no problem transferring stuff from the USB hard drive at full speed. I was actually pretty impressed with the speed, so impressed that I moved my USB hard drive to the router for sharing off the router instead of my PC.


odog
Cable Centric Vendor Biased
Premium,VIP
join:2001-08-05
Atlanta, GA
kudos:14
Reviews:
·Comcast
reply to jsmiddleton4

Just a rule of thumb, any time you amplify anything you add noise. In a bi directional system adding amplifiers also means putting in additional diplex filters. Diplex filters add to group delay.

Avoiding the use of amplifiers is recommended unless the power is so low on the receiving end, that the signal cannot be demodulated. Also when "feeding" an amp, good clean signal of a reasonable level is best. Amps have "sweet" spots where they want a specific input level in order to create the least amount of distortions on output.


lilstone87

join:2009-04-09
Portsmouth, VA
kudos:3
reply to digiblur

Like I said the drive format is NTFS, and I put money on it your drive isn't that format. As it's a known issue with the tomato firmware, when using a USB HDD that is formatted NTFS.


jsmiddleton4

join:2003-11-13
Glendale, AZ

I have been trying to test it and see if there is a slow down. Running into some *heads on linksysinfo though. Not sure why testing this and seeing if the proposed solution, setting the sendfile parameter in the smb.conf file, increases NTFS transfer performance.

None of which has anything to do with my AMP, no AMP matter however.

One of the forum Cox guys checked my lines, modems, and the AMP is staying off line for now.


lilstone87

join:2009-04-09
Portsmouth, VA
kudos:3
Reviews:
·Cox HSI

Well I know it's off topic, but yeah there should be a way to speed up the transfer rate's when using a NTFS usb HDD. As transfer rates are good on the stock asus firmware at around 12-14MB's range. I just know putting Shibby's firmware on the N66U, using my NTFS drive, and trying to transfer stuff to the drive, I get poor transfer rates of about 3MB's. Sadly If I remember correctly I asked Shibby about this on linksysinfo via PM, and didn't get no where with a solution to this problem. As I would probably use his firmware, but as of now 12-14MB's vs 3MB's using my NTFS HDD, there is no question I will stick with using Merlin's build.



digiblur
Premium
join:2002-06-03
Louisiana

said by lilstone87:

Well I know it's off topic, but yeah there should be a way to speed up the transfer rate's when using a NTFS usb HDD. As transfer rates are good on the stock asus firmware at around 12-14MB's range. I just know putting Shibby's firmware on the N66U, using my NTFS drive, and trying to transfer stuff to the drive, I get poor transfer rates of about 3MB's. Sadly If I remember correctly I asked Shibby about this on linksysinfo via PM, and didn't get no where with a solution to this problem. As I would probably use his firmware, but as of now 12-14MB's vs 3MB's using my NTFS HDD, there is no question I will stick with using Merlin's build.

Dunno what format it was, I believe it was NTFS though as I have several drives to swap in and out of the docking station. I got over 10mb a sec and was smiling like a kid in a candy store as the router just became a true all in one device. Merlin's wouldn't work as it was lacking features I required.

lilstone87

join:2009-04-09
Portsmouth, VA
kudos:3
Reviews:
·Cox HSI

Well Merlin replied to a post I made on linksysinfo regarding using a NTFS drive, and he said asus use a better NTFS driver, and that tomato uses a open sourced NTFS driver. Which has a rather poor performance in transfer rates, and suggested using ext3 format drive, if using tomato. The next drive I get I will make sure to format it ext3, current drive I will just use Merlin's build as it's pretty good, but does lack some added features tomato offers.


jsmiddleton4

join:2003-11-13
Glendale, AZ

I use the free EaseUS to format drives in EXT3. Easiest way I've found.

For me and my application/setting I'm sticking with Merlin's FW.

I like the fact that it is able to easily move back and forth between Asus stock firmware and his custom firmware. Have to send the guy a buck or two this payday.

It also is not only stable, its on the growth side of the bell curve. Tomato has just about run its course for features. I'm sure they could add a few more but it has so many now not sure what else they could add.

At this point Merlin is where the early Linksys/Tomato/DD-WRT stuff was a couple of years ago. Just beginning.

And I've been around Tomato a LONG time.



dvd536
as Mr. Pink as they come
Premium
join:2001-04-27
Phoenix, AZ
kudos:4
reply to jsmiddleton4

Work at home? uh oh. you have a biz issue.
--
Despises any post with strings.