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danny2324
19-07-2008, 19:07
I have an Ambit 255 modem on the 20mb connection. My speed is usually around 4-5mb, occasionally going to 11mb. I have an engineer visiting on Friday and just wondered does this information look right or does it need attenuating?

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 5
Downstream Frequency : 330750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 12.7 dBmV
Downstream SNR : 39.5 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 4
Upstream Frequency : 46200000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 43.0 dBmV
Upstream Mini-Slot Size : 2

I searched the forum but they seem to be for QAM256.

Many thanks
AbyssUnderground
19-07-2008, 19:32
The downstream is too high and should be as close to 0 as possible. +/- 5dBmV is acceptable though.
whydoIneedatech
19-07-2008, 19:34
I have an Ambit 255 modem on the 20mb connection. My speed is usually around 4-5mb, occasionally going to 11mb. I have an engineer visiting on Friday and just wondered does this information look right or does it need attenuating?

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 5
Downstream Frequency : 330750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 12.7 dBmV
Downstream SNR : 39.5 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 4
Upstream Frequency : 46200000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 43.0 dBmV
Upstream Mini-Slot Size : 2

I searched the forum but they seem to be for QAM256.

Many thanks

Both of the NTL platforms support QAM64 and QAM256

The Downstream is more than double what it should be so you need a Engineer visit,.
xspeedyx
19-07-2008, 19:36
wow that downstream is really high
danny2324
19-07-2008, 20:29
Great thanks, I'll make sure I don't get fobbed off!
whydoIneedatech
20-07-2008, 11:25
Great thanks, I'll make sure I don't get fobbed off!


Let us know how you get on.