I mentioned this in the DSL forum and it seemed people couldn't be less interested. The issue was "line or media quality". Anyone who knows anything about networking knows this is the single most important criterion for network performace. I work for a major phone company and can share a bit of insight into proplems you may have. I have been issued devices which definatively mearsure line quality and have had the chance to run tests on various components both inside and outside the house. If you have any questions please feel free to ask.
:-)
Line Quality
Here's one of the few places you actually have "control over" (sort of, more later on this). It's called the "drop". It's the link between your house and the phone companies network.
Types of drops:
AERIAL: Suspended in the air between the house and the phone line, terminal or pole.
Issues:
1.) REPAIRS. Look to see if the drop is one piece of wire or does it have repairs (splices). I have yet to have seen a repair which is water tight, via capillary action or whatever water gets in there and corrodes the splice. This significantly degrades line quality. The amount of corrosion is contingent upon the age of the splice. It is not uncommon to see a drop which is 60 years old and has had a repair made 30 or 40 years ago. Some of the houses I work on are over 100 years old. The average house is probably 50 years old. Guess what, at least half of the time the original or some portion of the original drop is still in place. Sometimes this is an issue with voice sometimes it isn't, but it is always an issue when multiplexing analog signals such as in the case of DSL. I have tested drops which have more noise in them than the 10,000 feet of wire going back to the CO.
2.) Wire type mainly UNTWISTED WIRE. Sometime in the mid or early nineties they switched from untwisted drop wire (CAT1) to twisted CAT3 drop wire. In most cases the drop runs parallel to the power companies drop to the house. Noise is induced this way.
How to tell them apart without opening them up:
CAT3 (Mid "90's through present): Rectangular in shape and has an 1/8 or 3/16 inch groove running down the center.
CAT1 new (Late "70's through mid '90's): Wire is about 5/16" wide with semi-rounded edges and a groove 1/16th inch groove running down the center.
CAT1 old ('20's or possibly earlier through '70's): 1/2" wide with rounded edges and NO groove running down the center.
Note: Drops are in the regulated (phone companies side) of the phone network and therefore are the responsibility of the phone company to maintain. In other words, if there is a problem with them they are repaired or replaced free of charge to the customer. If the drop were to become damaged it would be replaced free of charge.
BURRIED drops:
Burried between your house and a pedistal. The pedistal is located in your yard or one of your immediate neighbors usually. Since burried drops are not exposed to the weather they last a long time and can often be quite old.
Issues:
REPAIRS: Yes, they get damaged, many of these repairs are water tight it's just that they cannot be seen. The down side is they are voice quality repairs and not CAT3 quality. The repair person was not concerned with maintaining the CAT3 twist. Usually burried drops are not a problem unless they have bad repairs.
IMPROPER GROUNDING: Make sure that the shielding around the burried drop has a nice clean ground to your power companies ground (bonding).
NON-SHIELDED (old): I have seen instances where these get pretty old (even by phone company standards). The real problem is that they are prone to noise induction since the ground they are burried in is a semi conductor.
Finally there is a demarcation point which is what seperates your network (IW) from the phone companies network (in your case it is probably a drop). This demarcation point is call a NID or network interface device. NIDs are usually grey boxes on the outside of your house. There is a portion of this box which can be opened with a screwdriver and a portion which requires a security tool. The portion which requires a screw driver is the customer side and the portion which requires a security tool it the phone companies side. If you would care to see if your IW or inside wiring is slowing things down run a throughput test on dslreports.com, then open the customer side of the box and run a long phone cord from your modem to the jack in the NID. This will bypass all of your inside wiring.
Types of drops:
AERIAL: Suspended in the air between the house and the phone line, terminal or pole.
Issues:
1.) REPAIRS. Look to see if the drop is one piece of wire or does it have repairs (splices). I have yet to have seen a repair which is water tight, via capillary action or whatever water gets in there and corrodes the splice. This significantly degrades line quality. The amount of corrosion is contingent upon the age of the splice. It is not uncommon to see a drop which is 60 years old and has had a repair made 30 or 40 years ago. Some of the houses I work on are over 100 years old. The average house is probably 50 years old. Guess what, at least half of the time the original or some portion of the original drop is still in place. Sometimes this is an issue with voice sometimes it isn't, but it is always an issue when multiplexing analog signals such as in the case of DSL. I have tested drops which have more noise in them than the 10,000 feet of wire going back to the CO.
2.) Wire type mainly UNTWISTED WIRE. Sometime in the mid or early nineties they switched from untwisted drop wire (CAT1) to twisted CAT3 drop wire. In most cases the drop runs parallel to the power companies drop to the house. Noise is induced this way.
How to tell them apart without opening them up:
CAT3 (Mid "90's through present): Rectangular in shape and has an 1/8 or 3/16 inch groove running down the center.
CAT1 new (Late "70's through mid '90's): Wire is about 5/16" wide with semi-rounded edges and a groove 1/16th inch groove running down the center.
CAT1 old ('20's or possibly earlier through '70's): 1/2" wide with rounded edges and NO groove running down the center.
Note: Drops are in the regulated (phone companies side) of the phone network and therefore are the responsibility of the phone company to maintain. In other words, if there is a problem with them they are repaired or replaced free of charge to the customer. If the drop were to become damaged it would be replaced free of charge.
BURRIED drops:
Burried between your house and a pedistal. The pedistal is located in your yard or one of your immediate neighbors usually. Since burried drops are not exposed to the weather they last a long time and can often be quite old.
Issues:
REPAIRS: Yes, they get damaged, many of these repairs are water tight it's just that they cannot be seen. The down side is they are voice quality repairs and not CAT3 quality. The repair person was not concerned with maintaining the CAT3 twist. Usually burried drops are not a problem unless they have bad repairs.
IMPROPER GROUNDING: Make sure that the shielding around the burried drop has a nice clean ground to your power companies ground (bonding).
NON-SHIELDED (old): I have seen instances where these get pretty old (even by phone company standards). The real problem is that they are prone to noise induction since the ground they are burried in is a semi conductor.
Finally there is a demarcation point which is what seperates your network (IW) from the phone companies network (in your case it is probably a drop). This demarcation point is call a NID or network interface device. NIDs are usually grey boxes on the outside of your house. There is a portion of this box which can be opened with a screwdriver and a portion which requires a security tool. The portion which requires a screw driver is the customer side and the portion which requires a security tool it the phone companies side. If you would care to see if your IW or inside wiring is slowing things down run a throughput test on dslreports.com, then open the customer side of the box and run a long phone cord from your modem to the jack in the NID. This will bypass all of your inside wiring.
-
Musclemanfu2
- Regular Member
- Posts: 123
- Joined: Tue Jan 16, 2001 12:00 am
- Location: Danbury,Ct. USA
Very good post, Thanks for that info. ! It don't take much for your wiring to slow you down with DSL. DSL was slow at a house where speed was only 600kb. Down the road someone else was getting 1300kb. We tweaked and tweaked and still couldn't get past 600kb. Had phone Co. come out and check wiring. They found an old splice, fixed it, 1300kb after that.
I'm trying to give you an accurate a picture of the phone system without sounding synical. Generally the oldest neighborhoods are seeing rehabbing, the problem is that the inside wiring has usually been added on to and spliced dozens of times over the decades (both inside your house and on the phone companies network). To compound matters old segments are usually not taken out of service if they are still working (they usually are). Think of it this way. How many houses still use their original plumbing? You get the picture. Your best bet would be to install CAT5 wire on ALL segments of your DSL line, making sure you don't run it parallel within 12" of electrical conduits (if possible).