Our house in Taipei is on floors 5 and 6 of our building, the top two levels. Our phone lines come into the 5th floor and then there's a cable that connects up to the 6th floor phone jacks. My computer room is up on the 6th floor where the fax/adsl line goes. The cordless phone base station is in the study area off of Emily's room on the 5th floor. I have a VOIP account with Packet 8 as well, and it connects to the network upstairs and then was routed over the house wiring to the phone downstairs.
That worked OK, but there was a little bit of noise on the line. It wasn't much at first, but it got worse over time, until sometime in May it got to the point where it would be unusable at times. So I needed to find out the problem and fix it. The first problem was finding out where the cables were routed. I finally figured that all out, and found that almost every pair between upstairs and downstairs was flaky. It's amazing that the ADSL line managed to keep working under the circumstances.
That meant having to run a new line between upstairs and downstairs. While I was at it, I decided to put in an ethernet line as well so that I could put network stuff downstairs in the future. (There's already an ethernet drop running to the front of the 5th floor for wi-fi, but the back of the house didn't have any network drop.) This involved going to the SL store to get cables, jacks, cable ties, and a monster drill bit to make holes in the walls. For the phone lines they had four conductor cables, and I got some cat 5 cabling for the ethernet drop. I planned to run two phone cables and one network cable, which would allow for one network drop and up to four analog phone lines.
I decided to have the cables take a fairly direct route from the computer room through the wall to the stairwell, down the wall, and through the wall again into the study area. Drilling the holes went remarkably smoothly, as did feeding the bundle of three cables through. The hardest part of that was getting the cables to lie neatly and then get the cable ties nailed down.
I got the main house line and the adsl line going up through the new cables, and once the adsl line was over on that line, I cut out the link between the 5th and 6th floors on the inside wiring. I routed the VOIP back down over the other line and hooked it up to the phone, and when I tried it out, the sound was crystal clear! Success.
Of course, it wouldn't be that easy! Getting the network cable working was another matter. Though I bought what looked like two identical RJ45 jacks, they turned out to have completely different layouts for the connects inside. I wired things up with identical color schemes to match the labels on each end, then plugged a patch cable from one end into the switch, and on the downstairs end another patch cable to the laptop.
On the laptop, I disabled the wifi port and enabled the ethernet port, and then sat staring while it waited at "Acquiring network address". Suspecting something wrong with the DHCP server, I set it up in debug mode and found that it was seeing and answering the requests correctly. That seemed not to be the problem. Then I replaced the switch upstairs with a different one and that worked a bit better. It was able to get an address sometimes, but then it was a bit erratic accessing the network.
With ping, I was able to see there was some amount of packet loss. Not too bad for small packets, but up around 8k packet size it was losing about 20%. Not good at all. Suspecting that the cable might not be to spec, I set the laptop to 10mbps instead and that worked just fine. In case it was a bad pair, I inverted from using the orange and green pairs to using blue and brown. (Ethernet cables use 8 conductors, but normally only 4 are used.) That didn't work any better. But by hooking up only two pairs at a time, at least I was verifying that I was at least wiring the jacks correctly.
The cable I was using on the laptop end was kinda old, so suspecting it next, I swapped that one out. The problem got worse! But this turned out to be the crucial clue into what was going on. Between the upstairs end and the switch, I'd installed a new cable right out of the bag. When I replaced the downstairs cable with the same brand of cable right out of the bag and it got worse, I finally realized that it was those patch cords that were the problem. Though the package said they are Cat 5e rated, the cable itself didn't have Cat 5e written on it. I suspect someone cheaped out and used out of spec cable and hoped nobody would notice.
Swapped those bum cables out with another set of brand new cables straight from the bag (this time verifying that the cable itself has CAT 5 stamped on the jacket), and things worked beautifully! Still had to rewire the cable again back to the proper color coding and tested again, and now it's all working great.
Just goes to show that sometimes the thing you expect the least (a brand new cable straight out of the bag) is the one thing that was causing all the problems. Anyways, now we have the phone lines in better shape than ever, plus a network drop to the study downstairs, so I guess it was all worth it.