[Sephiroth]

Originally Posted by CPCUK

Hi,

This may be a really dumb question but I'm gonna go ahead and ask anyway.

When I was on 50Mbit and QAM64 I got 50Mbit on speedtest sites. Quite a while back now I noticed that I was moved over to QAM256. My power levels went quite high (from around 0dB to 13dB) but everything seemed fine. I added an attenuator to bring it back to around 0dB.

Anyway, I've noticed that my downstream channels are not consecutive, ie, 158,157,159,160 and although it might just be me clutching at straws I noticed that on speedtest sites I only obtained around 30Mbit to 45Mbit speeds. Logically I assume they are simply channel names and nothing more rather than required to be consecutive (as I said its a daft thought, lol).
[SEPH]: They don't have to be consecutive, but they do have to be at a frequency separation no greater than 8 MHz one between the other as if they were a consecutive group

Having upgraded to 100Mbit yesterday the engineer said that I should receive good download speeds.....we both laughed when I received 30Mbit!!!

To be honest I wasnt happy but I thought I'd se how things went. The engineer stated that my actual area shouldnt be too heavily populated with subscribers too!

Anyway, I ran 14 simultaneous downloads this morning which equated to around 12MB/s of downloads (great!) but why cant I see this speed on speedtest sites?
[SEPH]: It's the downloads that matter. I get crap speedtest reports but better download speeds from sites with good bandwidth that are not busy. I don't know what's gone awty with speedtest.net, but I don't trust it any more.


I stopped getting full speed I'm sure when I was swopped over to QAM256 six months or so ago.
[SEPH]: When you went to QAM256, you went onto a different line card and most prolly with competing users whose activity is affecting you worse than when you were on the old line card. Contention, in other words.


I've also right now got 18dB of attenuation on the coax at the modem to give me a 0dB level? Should I require this amount really as it used to be around 6dB i the past.
[SEPH]: It depends what the engineer did at your street cabinet. Your level would rise if the engineer put you on a lower attenuation tap point, and it would be that high if you were near to the street cabinet. Or, they've replaced a weak amplifier in your street cabinet and suddenly, woomf.


Superhub power stuff shown below (looks ok to me)
[SEPH]: Yep - fine


Any help appreciated

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Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 443000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK
Security Enabled BPI+


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Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 158 55616000 Kbits/sec 443000000 Hz 0.0 dBmV 41.5 dB Hybrid
Locked QAM256 157 55616000 Kbits/sec 435000000 Hz -0.3 dBmV 41.4 dB Hybrid
Locked QAM256 159 55616000 Kbits/sec 451000000 Hz 0.0 dBmV 41.5 dB Hybrid
Locked QAM256 160 55616000 Kbits/sec 459000000 Hz 0.0 dBmV 41.5 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown


--------------------------------------------------------------------------------

Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 3 20480 Kbits/sec 45800000 Hz 42.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV



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Primary Downstream Service Flow
Downstream(0)
SFID 10857
Max Traffic Rate 110000000 bps
Max Traffic Burst 10000 bytes
Mix Traffic Rate 0 bps


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Primary Upstream Service Flow
Upstream(0)
SFID 18540
Max Traffic Rate 10250000 bps
Max Traffic Burst 16320 bytes
Mix Traffic Rate 0 bps
Max Concatenated Burst 16320 bytes
Scheduling Type Best Effort