A few more 50Mbit questions

[CPCUK]

Hi,

I have had 50Mbit for a few weeks now and upon testing it I am happy to report that 99.99% of the time get just over 50Mbit down and 1.65Mbit up.

Anyway, I am on a 64QAM Modulation and although I have looked around for recommended power levels and other info for this I still dont know what they should be for 64QAM. I think they are different from the 256QAM Modulation 50Mbit.

I have a bunch of attenuators here and I have fitted one to give me a downstream power level of around 0dBmV (just slightly over on 3 of the 4 channels) which I believe is what I am ideally aiming for. My RxMER level is 30 on all channels, is this ok for 64QAM or a bit low?

The reason I ask is that I am receiving hundreds and sometimes I even reach thousands of "correctable" and uncorrectable" codewords on the modem's downstream page. Should I be receiving this many?

My upstream uses the 16QAM Modulation and I have have 40dBmV which I guess is fine although I have had a single "T3 timeout".

One thing I do notice is that when testing my speed using speedtest.net is that when running the test I have a lot of stuttering going on between 0 and 1Mbit and then that goes and I fly straight around to 50Mbit on the dial.
Is there any reason for this and could it effect online gaming in anyway?

Thanks for any help.

[Peter_]

Your power levels seem fine especially if you are getting your full 50Mb.

[CPCUK]

Thanks for your reply.

Yep, I am getting the full 50Mbit which I'm happy about :)

Do those codeword errors mean much?

Also, the modem log shows some errors which I have seen others with. Are these of any concern?

Map Request Retry Timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Jul 8 15:02:29 2009 Wed Jul 8 15:02:29 2009 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx:;CM-QOS=1.1;CM-VER=3.0;


Thanks again for your help.

[Peter_]

My standard reply regarding modem logs is below.

Be careful of reading modem logs, because what happens when you reboot your modem is that every single update for that modem is received at the same time giving you those worrying logs.

Virgin also disable most of the updates as they are not required so making it look even worse.