I have Qwest standalone 1.5 Down / 864 Up DSL service at a store location that is near the distance limit from the CO. My connection is marginal, so my Cisco 678 is retraining quite frequently.
Qwest has concluded that the best solution is to slow down the line. However, due to some kind of tarriffing issues, they can't do this on a stand-alone DSL line. I don't have any regular phone lines at this location (all my voice lines are ISDN), so I can't get slower service unless I add an analog line, which would result in a total cost almost double of a standalone DSL line.
My question: Is there any way to configure the Cisco 678 to force a limit on the maximum speed of the Up and Down connections?
It looks like you can set the rate via the set interface wan0 rate command, but I've never tried it. Here's a link to the Cisco documentation on the
67x - CBOS:
I ran into a similar problem with a client who added DSL to a dedicated phone line - as it turned out, the phone wiring in the office had been expanded numerous times over the years, and there was a lot of crosstalk and interference with all the added analog phone lines plus their small digital PBX. I ended up running a dedicated phone wire from the office straight to the Network Interface (NID), and disconnected the existing wiring going through the building for that phone line and it solved the retraining problem. You might gain a few dB of signal quality if you don't have a direct line to the NID.
Have you tried "sweet talking" Qwest into possibly getting a tech to come out to the store, and check the wiring from the NID back towards the CO? Possibly they may find a bad splice or connection, and you might gain some signal quality.
Another thought - poke around or join in on the discussions about Qwest on
; maybe some of the group over there could offer some additional suggestions. I have heard of consumers having speeds lowered to improve reliability, but I don't have any experience with the stand alone DSL service, or the business service.
Mike, You need to get your telco out again, I believe you are having a problem with "bridge tap", even short lengths like 50' can affect your speed or cause retrains on long loops. The tech will need to use a TDR (Time Domain Reflectometer) in Qwest territory they use the 3M 965DSP, but other telcos may use something else, of course then you need a tech that knows how to interpret the results! Here is a site that explains bridge taps:
I am also on a long loop (27,500') from the telco central office on 22 gauge cable. I had to have several bridge taps removed, I am only able to get 256K/640K but it beats dial up anytime. I am also using the Actiontec
1520 that has the globespan chipset and is better than the current Actiontec GT 701 that uses the TI chipset. The 1520 gave me an extra 3000 feet over the Cisco 678. Here is how to possibly up your SNR level, if you go too far you will lose train, in effect by dropping your tx power the DSLAM at the CO, ups their TX power (your receive power), it worked better on the older CAP circuits using the 675, but there will be some change with DMT and the 678. To change the transmit power and thus bring up the receive level or line quality use the following:
Set int wan0 txpower (1-6) for 675 1 is default?.each change will drop txpower by -3db (678 can use 1-12)
Set int wan0 retrain (after changing, to test results?.then use the "write" command)
The phone company runs a long cable past your house and up the street.
When they connect you, they run a shorter line (a drop line) from the house to that long cable. Then they connect to a pair of wires. They could cut the street cable at that point, and connect to your drop line. But usually they leave the street cable intact and just connect your drop line to it. The "bridge tap" has to do with the unused part of the street cable that extends from where you are connected and away from the CO toward the end of the cable. Something similar can happen where your street cable connects to a mainline cable somewhere closer to the CO.
They prefer not to cut, because that would reduce the usefulness of the pair if you discontinue service. However, they usually will clean up these bridge taps if that is needed to get you reliable DSL service.