Speed and ping way low today DN35 - Page 2

pip08456 · 01-06-2011, 21:16

What the Ambit256 is spec'ed for is immaterial. The pertinant issue is what the VM network is spec'ed for. A read of THIS will be helpful to you.

craigj2k12 · 01-06-2011, 21:19

however masque say they work to +11 now, probably trying to save money on techs

anyway a power level of 10 will not cause the problems the OP is having

pip08456 · 01-06-2011, 21:20

Quote:

Originally Posted by craigj2k11

just ring virgin, i think pip is resorting to alcoholism at the moment he is having mood swings like a pregnant woman. either way you will need to ring virgin, then they will tell you if there is an area fault or a power level problem

Time for a drink then!!!

JPAC · 01-06-2011, 21:21

That's the page I got the information from; CABLE MODEM NOMINAL SPECS

Thing is why today? Worked OK before, I'll get on to VM tomorrow.

Thanks all.

pip08456 · 01-06-2011, 21:25

Quote:

Originally Posted by craigj2k11

however masque say they work to +11 now, probably trying to save money on techs

anyway a power level of 10 will not cause the problems the OP is having

As I have said many times you have to have to rule out the obvious first, it's a logical progression.

2nd line on VM's website would book an engineer out first before trying to diagnose further.

Quite a few of the beloved VMNG300s refused to lock on to a downstream above 7dB. The higher spec Masque refers to could be hub specific. We are not discussing a hub here though.

---------- Post added at 22:25 ---------- Previous post was at 22:24 ----------

Quote:

Originally Posted by JPAC

That's the page I got the information from; CABLE MODEM NOMINAL SPECS

Thing is why today? Worked OK before, I'll get on to VM tomorrow.

Thanks all.

That is a page from where? It's not a link to it. Try THIS one.

craigj2k12 · 01-06-2011, 21:28

lets all get smashed and have a big argument

pip08456 · 01-06-2011, 21:29

Quote:

Originally Posted by craigj2k11

lets all get smashed and have a big argument

Hugh would only step in and put us in the sin bin for 24 hrs.

craigj2k12 · 01-06-2011, 21:32

Quote:

Originally Posted by pip08456

Hugh would only step in and put us in the sin bin for 24 hrs.

id need at least that in recovery time

JPAC · 01-06-2011, 21:32

Quote:

Originally Posted by pip08456

That is a page from where? It's not a link to it. Try THIS one.

That is the heading from the page you linked to, which said
the Ambit 256 modem is spec'd for downstream in the range -15 to +15 dBmv

Choosing a different server now on Speedtest is giving a lot steadier graph.

pip08456 · 01-06-2011, 21:37

You didn't carry on reading though did you?

"At this point, more needs to be said about the downstream. As most of you know, the downstream RF signal is is QAM modulated (which you can read about here). High power levels can cause QAMs around the tuned one to break through the tuner's isolation and interfere with the intended signal.

RECOMMENDED POWER LEVELS

Bearing in mind the above explanations, it should be clear why the following levels are recommended. They take into account

the modem's specifications
the technical explanations provided above
the anecdote on the forums as to where problems arise
the values based on geography (i.e. network build) recommended by Virgin Media staff

DOWNSTREAM POWER (Optimal)

Rule of thumb: -3 dBmv to +6 dBmv

The above advice compares with the VM stated optimum values by region (according to implemented infrastructure standards) and modulation:

QAM64 (Knowsley networks) -7 dBmv to +3 dBmv

QAM64 (Langley/Bromley) -10 dBmv to 0 dBmv

QAM256 -3 dBmv to +7 dBmv

This is not cast in stone. A good modem (Cisco 2100 comes to mind) can handle nearer the DOCSIS spec if the level is steady and the experience good. If the experience is bad, then look for high downstream power, particularly above the 9 dBmv mark."

JPAC · 01-06-2011, 21:42

Quote:

Originally Posted by pip08456

... If the experience is bad, then look for high downstream power, particularly above the 9 dBmv mark."

OK, so if the level is too high, would the CM stop working altogether or would it cause the spikes in the download speed shown in the graph?

pip08456 · 01-06-2011, 21:55

Certainly, as mentioned above there were many VMNG300s that refused to lock onto the primary downstream channel above 7dB therefore -no service.

Plus there is this.- High power levels can cause QAMs around the tuned one to break through the tuner's isolation and interfere with the intended signal.

I don't think it's necessary to get any deeper into it. Suffice to say until the power level is rectified further investigation is pointless.

Kursk · 02-06-2011, 00:49

Quote:

Originally Posted by JPAC

0.37Mb/s dl, 0.365Mb/s up and ping is 1017ms, anyone else? 10Mb/s normally.

Just a thought but have you installed anything new on your pc lately? The reason I mention it is because I switched from Virgin's AV to another security solution just last week and my connection speed went down the swanee much like yours.

I realise this is a basic question but sometimes we do go off looking for complicated answers to simple problems.

JPAC · 02-06-2011, 08:31

Hi, I updated Malwarebytes to the latest version yesterday but I don't normally have that running. The speed and ping were up and down every few minutes, some web pages took ages to show and news video kept buffering.

pip08456 · 02-06-2011, 08:36

Can't see MWB causing any problems.