Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[GigabitEthernet]

So why have I raised a fault then - *sigh*

[les-70]

 As I said a long while ago you may just have a noisy line. My own view is that if an engineer is on their way then just focus on the variations in SNRM, mention the the odd resyncs and suggest that your seeing more RFI pick up than you think is normal. However note that the RFI  seems to be in the evenings so the engineer won't see it. 

   A pair swap might help but if it is noise source and not a line fault the new pair may be better or worse.  Your line attenuation is very steady so I doubt there is an HR fault. As I mentioned the recent drop in overall attenuation is only a side effect of a minor loss of D3 tones.

 My line is noisy but I cap the sync speed to the speed levels which occur with interleaving and this avoids interleaving occurring due to odd noise bursts.  It annoys me that an event which does not occur most weeks is enough to keep me interleaved unless I cap the speed to soften the impact.  Maybe G.INP will help when/if it gets to my ECI cab.

[Dray]

That's the sort of thing that a line fault, e.g. corrosion, can do.

[GigabitEthernet]

Well no the RFI would appear to be all the time wouldn't it, hence the reduced bitloading?

[GigabitEthernet]

This line for instance:



It shows most of the tones available for the upstream (and the downstream) and yet only manages an upstream sync not faster than mine.

How is my line able to achieve the same sync but with only half the tones being used? It would seem to indicate that the tones that are being used are of a higher quality and so if we could get those other tones to be used also, this might increase the upstream sync?

[GigabitEthernet]

I've just remembered about the time when I had a powercut and the connection came up first before the other lines, resulting in a 10Mb gain in sync. This was presumably due to all outside sources of interference being temporarily removed.

The Hlog and QLN graphs still looked the same however.

This would seem to imply that there must be another issue?

[NewtronStar]

This pair swap thing let me see if i am correct lines have three pairs the 1st pair is the A & B connected to PCP cabinet and terminated to Master Socket A & B the second pair is A & B but not connected at PCP cabinet or Master Socket the third pair is the bellwire and earth.

What happens if the 2nd pair is worse than the original 1st pair ?

[Black Sheep]

This pair swap thing let me see if i am correct lines have three pairs the 1st pair is the A & B connected to PCP cabinet and terminated to Master Socket A & B the second pair is A & B but not connected at PCP cabinet or Master Socket the third pair is the bellwire and earth.

What happens if the 2nd pair is worse than the original 1st pair ?

You only have ONE external pair from the Cab to your premises (unless you have a multi-line installation). The older internal wiring has THREE pairs, but they will only travel as far as the internal wiring travels. The bell-wire is not necessary on most modern phones, and the micro-filters have a ringing capacitor in-situ to ensure the older type phones ring without the need for the bell-wire.
There is no 'Earth' on any other pair of wires other than the 'feed' pair. 

[GigabitEthernet]

BS, could you explain the process of a D-side change?

If the cable is overheard like my line is, there are multiple lines in one cable so to change the whole cable would take other customers offline too?

Thanks again as always my friend

[NewtronStar]

You only have ONE external pair from the Cab to your premises (unless you have a multi-:)

There was me thinking it was like a Cat5 cable with 3 pairs.
What is a pair swap when you are still using the same pairs as you did before ?

[Black Sheep]

You only have ONE external pair from the Cab to your premises (unless you have a multi-:)

There was me thinking it was like a Cat5 cable with 3 pairs.
What is a pair swap when you are still using the same pairs as you did before ?

Underground D-side cables have a variety of sizes ...... from 1pr to 100pr. Ideally, if there is a fault identified on the UG cable it should be located and repaired if possible, however it depends on the visiting engineers skill-set as to whether this will be done. I'm not going into the why's and where-for's  but it is suggested that a 'pair change' is carried out with some skill-sets. This means putting the circuit through a different pair from Exchange to Cab, or Cab to DP. Of course, the new pair has to test ok before this is done.
Of course, there is a an acceptable argument that if one pair has gone faulty, then others will as well in time. But the business has obviously done a costing exercise on this and deemed 'pair changes' to be acceptable.

So, to answer your question, you are not using the same pair as before from the Cab to the DP / Exchange to Cab. You are still using the same pair in the internal cable though.

[NewtronStar]

So, to answer your question, you are not using the same pair as before from the Cab to the DP / Exchange to Cab. You are still using the same pair in the internal cable though.

But From the DP to premises it's still using the original pairs (Drop Wire) to your premises is that right 

[burakkucat]

But From the DP to premises it's still using the original pairs (Drop Wire) to your premises is that right 

Absolutely correct. 

And testing the pair in that cable would be the easiest task.

I've attached a page, below, showing the typical specification of a two pair drop-cable.

[GigabitEthernet]

So the physical cable between the cabinet and the DP is never actually changed?

[NewtronStar]

So the physical cable between the cabinet and the DP is never actually changed?

No not the underground cable as it looks like there are plenty of cores (pairs) in the cable for pair swaps