100M : Decreasing Power Levels

[adduxi]

Not too sure if I should be concerned, but I'll throw this open to the floor.....

For many months now, I've noticed my DS power levels have been slowly decreasing. Originally they were about 2db, but now they are heading towards -3.5db

The US is fine and has had no noticeable changes for ages.

Any suggestions as to why the slow creep downwards? Should I panic ....

[qasdfdsaq]

a) Degradation of equipment
b) Global warming
c) VM signing up more customers

Whether you panic depends on how paranoid you are about the above.

[General Maximus]

mine went down by a few db went they did the doubling upgrades in my area last month. Even though they have gone down to -5 at times my speed has never suffered for it so I wouldn't worry too much about it. I think they do down a few db as the weather gets colder as well.

[Sephiroth]

You might have changed downstream frequences to a higher frequency bonding group AND you are some way from the street cabinet.

[General Maximus]

yeah, I dont know where my cab is but it definitely isnt anywhere near my house, As for DS frequencies, I was on channels 24-27 before and I can remember one of them being 297000000hz. Now I am channels 1-4 and it starts at 267000000 so it looks like it has gone down and not up.

[kwikbreaks]

Originally Posted by General Maximus

I think they do down a few db as the weather gets colder as well.

Downstream power will rise as temperature falls as the falls because the copper resistivity decreases with temperature. It won't be anywhere near the reported change though. Upstream could fall with temperature as that's a measure of how much juice your modem needs to produce to hit the target noise margin which does decrease as the temperature and resistivity fall.

If it was a gradual decline it might indicate something slowly degrading but it it was one or more step changes it's probably just network changes. When I got a Superhub to replace my VMNG300 I found that the downstream levels were reported as being much lower so I left out the FP attenuator which I had with the VMNG300.

---------- Post added at 08:49 ---------- Previous post was at 08:46 ----------

Originally Posted by General Maximus

yeah, I dont know where my cab is but it definitely isnt anywhere near my house

Could it be underground? I think all cabs have to be within a couple of hundred meters - no doubt one of the VM installers can comment on that.

As an aside mines about 100m away and a car has just hit the wall inches from it so I had a lucky break there even if the car driver didn't.

[adduxi]

Originally Posted by kwikbreaks

If it was a gradual decline it might indicate something slowly degrading but it it was one or more step changes it's probably just network changes.

Thanks for all the replies, but this downward creep is over a long period of several months, so I guess something is about to give up.....
The original cabling is all from my NTL days of 512kb broadband, so I guess it could be corrosion somewhere on the line.
I might have a look in the external wall box as the internal cable all looks fine.
Cheers !!