Ideal signal strength to NTL modem

christophicus

Hey guys I was wondering if you could help me. For the las t week or so my NTL connection has been droppping off once or twice a day, but it ready light stayed fully lit. I think it may be the quality of teh signal coming to the house is dipping . Can anyone tell me what the ideal signal measurements are?

When you go here 192.168.100.1 and then to cable downstream these are the last two

Downstream Receive Power Level : -6.6 dBmV
Downstream SNR : 37.6 dB


I think the SNR is ok , but I think the power level should be higher ( eg closer to 0 ) . Any info at all would be much appreciated

Cheers
Chris

watty

If the SNR is OK the downstream level doesn't matter. It can be much lower. Maybe the upstream is too high. If the upstream is more than 50dBm then that is the problem.

> 30dB SNR is fine

blue_man83

When you go here 192.168.100.1 and then to cable downstream these are the last two

Downstream Receive Power Level : -6.6 dBmV
Downstream SNR : 37.6 dB


[/QUOTE]

Hi Chris

Your power levels look ok to me. Like you say, it would be better if the Recieve Power level was closer or above 0 but until i goes over about -12 you dont have to worry about that being your problem.

It could be possible that when your broadband cuts out that its dropping below -12 but a dip like this would mean a bigger problem.

Whats your set up? i.e. wireless, how many computers connected, speed etc?

christophicus

Thanks for the replys guys I really appreciate it.

Yeah Watty the upstream is 60dBmV

Upstream transmit Power Level : 60.0 dBmV

When the engineer came to my house he said that anything between 4 and -4 was good. Mine is 6 so that is not good , if he was right.

My setup is

modem > D-link 4300 >PC(wireless)
> PC (wireless)
>PC (lan)
> DS

DingDong

-6 isn't that bad it really depend on where you live, in an upgraded area it should be closer to 0 or a plus value. Your modem is working flat out it transmits up to 61 before it knocks itself off. It usually indicates a problem on the network. Is the cable going to the modem going through any splits ?

JPA

What's the login for the NTL modem page? I can't remember.

christophicus

Thanks for the help guys yeah its going through a spliter

lol JPA the username and password are both root.

donal.hunt

these are the levels I've recorded over the past 5 days or so from my modem in dublin 12:

Downstream Power: 9.2 - 10.3 dBmV
Downstream SNR: 35.1 - 36.8 dB
Downstream Power: 36.5 - 38.0 dBmV

For those of you running linux boxes, you can pull snmp data from the box and graph it using CACTI. There's even some templates available somewhere (i can dig out the URL if you want it) for the AMBIT cable modems.

so far i've see regular t3 timeoouts and 1 t4 timeout (corresponds with an interface reset).
last friday evening was abysmal for connectivity so I'm hoping the above setup will highlight when there is an issue.

christophicus

Thanks for that man, its good to have something to compare to . I did not understand anything in your third paragraph though.

okcomputer

is there anything you can do when your ready light goes on the blink?

christophicus

Nope not really.