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billaustin
they call me Mr. Bill
MVM
join:2001-10-13
North Las Vegas, NV

billaustin

MVM

[ALL] Signal Questions / Amp Location

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I'm a new Cox Customer. I have 25/5 Business Service with Telephone installed on August 8th. I've been using 10/896 DSL for seven years, and Cox finally ran cable down my street in June. The installer had to use an amp to get the signal levels up to an acceptable point, but I'm not sure it is in the ideal location.

The drop from the street is overhead, about 75 feet. It goes inside to the old OTA splice point, and then connects to a single cable out to the modem. The run is about 160 feet to the next junction point. The splitter was replaced with a single junction, and then it runs about 30 feet to the modems. The internet and phone modems are each connected to an output port on the amp.

Most of the time, everything seems to work fine. I have Netwatch setup in the router. It pings the gateway every minute, and sends me a text when it fails, and then when it recovers. Sometimes it will go hours with no problem, and sometimes I'll get a burst of 10 to 30 all at once. It seems to average about six drops during the night and about 18 throughout the day.

Any comments and suggestions are welcome. I've attached screenshots of the signal levels.

AnonPhx
@70.209.66.x

AnonPhx

Anon

An amp works only with good input signal. Ideally the amp is installed at the end of the drop at dmarc. If an installer put an amp directly behind a modem then it is doing nothing but taking all the noise that is on that line, amping it up and slamming it into the modem. By your discription your modems are plugged into one port feach on a two port amp. A two port amp will result in a 11db gain so if we subtract 11db off what your modem is reporting then your amp is seeing inputs at -11 or -12dbmv. Cox standards are no less then -10dbmv and rather then put a small ammount of work in to install the amp at dmarc, the installer would rather wreck the service so it appears like the modem is getting good signal when it really is getting wrecke with noise.

Hard Harry7
join:2010-10-19
Narragansett, RI

Hard Harry7 to billaustin

Member

to billaustin
I would call and ask them to put your modem on monitoring. That way when the packet loss occurs they can match it up with any signal changes to the modem. Then its a matter of what is causing those signal changes.

Also, when you get packet loss to the gateway, does the phone have problems? Last, what are the problems reported on site? Does the packet loss manifest as lost connection? Slow? Etc?

antonio010
join:2002-11-24

antonio010 to AnonPhx

Member

to AnonPhx
This is correct. The amp should have been installed at the dmarc. Ideally there should have been a CE installed at the dmarc/pop and the amp put in there. That amp is not boosting a signal in the proper range.

The transmit levels of the modem also need to be addressed.

billaustin
they call me Mr. Bill
MVM
join:2001-10-13
North Las Vegas, NV

billaustin to Hard Harry7

MVM

to Hard Harry7
I have not noticed any problem with the phone, there are some slowdowns with the internet.

I'm going to move the amp up to the beginning of the long cable run and see how that works.

Anonguy
@68.106.20.x

Anonguy to billaustin

Anon

to billaustin
As everyone else has stated, yes the amp is in the wrong spot.

But another problem, Assuming all the wire is RG6 and your distances are correct. The plant signal seems off...

Over 265 feet you should lose 16db of signal. Without the amp you are at -11 at the modem. That makes the tap level at +5. That is at least 5db low and maybe more. ALso how many phone lines do you have? If 2 or less you should be able to use one modem for both.

Can you see the tap(hookup) on the pole? It will have a number on it like the 23 on this one:
»www.arrisi.com/products/ ··· tf-p.jpg

What is the number?

Last thing,

Edit the MAC's out on the phone modem screenshot. Not safe.

billaustin
they call me Mr. Bill
MVM
join:2001-10-13
North Las Vegas, NV

billaustin

MVM

I have not looked at the tap on the pole. The new overhead cable run is about a half mile long and was put up three months ago. I am the first customer connected to it (about 600 feet from where it begins). The Cox Tech that installed the drop did have to go adjust signal levels where the new run connected to the existing system. The rest of the installation was done by a Cox Contractor.

Anonguy
@68.106.20.x

Anonguy

Anon

How far away are you from the tap? Is the tap on that pole that is 75 feet away or another pole?
Anonguy

Anonguy to billaustin

Anon

to billaustin
said by billaustin:

I have not noticed any problem with the phone, there are some slowdowns with the internet.

I'm going to move the amp up to the beginning of the long cable run and see how that works.

I wouldn't do that yourself,

First you need a power passing splitter at the modems to get power to the amp.

Second you would need a 1 port amp, not a 2 port. An open port is never a good thing.

billaustin
they call me Mr. Bill
MVM
join:2001-10-13
North Las Vegas, NV

billaustin to Anonguy

MVM

to Anonguy
said by Anonguy :

How far away are you from the tap? Is the tap on that pole that is 75 feet away or another pole?

The tap is at the pole. The drop from the tap is about 75 feet long.
billaustin

billaustin to Anonguy

MVM

to Anonguy
said by Anonguy :

said by billaustin:

I have not noticed any problem with the phone, there are some slowdowns with the internet.

I'm going to move the amp up to the beginning of the long cable run and see how that works.

I wouldn't do that yourself,

First you need a power passing splitter at the modems to get power to the amp.

Second you would need a 1 port amp, not a 2 port. An open port is never a good thing.

Why make it so difficult? The power injector is attached to the amp. I'll just move them both together and plug it in at the other location.

I'll just put a terminator on the second port, or connect it to the old OTA wiring. The installer told me basic cable was there if I wanted to connect a TV to it.
billaustin

billaustin

MVM

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New Amp
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Phone Modem
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Cable Modem
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Cable Modem
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Old Amp
I thought I would post an update. I moved the amp to the beginning of the long cable run, and it helped. When I replaced the amp with a splitter at the modem location, I watched and the drop in signal level was about 14db. Since the amp provided by the installer only provided 11db gain, I replaced it with a 15db unit. I turned the forward gain up to about 99% and the reverse gain down to around 1%. Here are the new levels. I also noticed the errors have disappeared.

bbeesley
join:2003-08-07
Richardson, TX

bbeesley

Member

There are two things I take issue with your install that really should be corrected lest you have problems in the future

first, unless their policy has changed Cox doesn't allow installers in Vegas to use return passing amps because they can amplify return noise and cause issues for other users on the node.

second, it's a terrible idea to use an non-plant powered active to correct low signal for phone installations. If there is a power outage, your amp will loose power and your levels will drop, the eMTA will go offline and you won't be able to make a phone call, which could be really bad in an emergency situation, especially at business where you might have liability for your employees or customers.

a 75' drop shouldn't be a problem. If the levels aren't correct, that really needs to be addressed by the plant maintenance folks, not the contractor doing the install

billaustin
they call me Mr. Bill
MVM
join:2001-10-13
North Las Vegas, NV

billaustin

MVM

The 75' drop from the pole is not a problem. It's the additional 190' out to the modem that causes issues.

I don't know what Cox policies are in regards to amp installations. The installer originally installed the amp at the end of the run feeding into the modems. I moved it to the beginning of the run, then replaced it with another model. I bought that particular model because the gains were adjustable.

I have multiple UPS units powering all the equipment, so I'm not too worried about that.

bbeesley
join:2003-08-07
Richardson, TX

bbeesley

Member

said by billaustin:

The 75' drop from the pole is not a problem. It's the additional 190' out to the modem that causes issues

That shouldn't be an issue with RG6 - you are only loosing 6db per 100' at 800Mhz

ideally, I would use RG11 for a 300' install but it shouldn't be necessary.

The amp is a really bad idea based on my experience with a decade an a half of commercial installs. Even with the UPS.