Hi again Mark,
Much of the following is really repeating what you can find with the link Jeff has given you.
It's important to approach line improvements in a logical way, preferably recording all the steps you take with their results.
You should certainly start by eliminating all possible problems with internal telephone wiring. A significant number of problems are caused locally with poor, incorrect or star** wiring.
Assuming you don't have star wiring***, if you start from the test socket, but including your filter there, you have disconnected all your internal wiring so it can no longer interfere.
If possible leave it for an extended period in this configuration and observe the modem's performance.
** Star wiring is usually obvious if you have any internal or external junction box where one wire goes in and several come out.
*** If you DO have star wiring you'll need to remove ALL bell wires throughout the house
Without any ringwire the iPlate would make no difference at all. The filters supplied with the 585 are usually about as good as you can get, although you might just have a faulty one.
Unless the filter is faulty there's usually little to be gained by using others. (Except that at one stage some filters looked similar to a phone line splitter and some of those were of poorer quality.)
An integrated filter in the master socket such as those illustrated here look a little tidier but in my experience don't usually make a significant difference.
http://www.adslnation.com/phpapps/catalog/index.php?cPath=24Once you have proven your internal wiring it's then necessary to monitor the line itself. Routerstats Lite is a simple program which allows you to monitor both noise margins and the modem's sync. speed.
See:-
http://www.kitz.co.uk/routers/log_routerstats.htmA version is available for the 585. Leave it running whilst you do the following tests, and probably leave it ovenight at least.
Firstly do a 17070 option 2 quiet line test with a corded phone plugged into the test socket. As its name suggests you should hear nothing but the test announcement.
Then follow up with a couple of ring-back option 1 tests. You might see a 0.5 dB noise fluctuation a little while after dialling or answering, but it should not cause the line to drop sync.
If all these things seem to be correct just monitor the line for a few days.
You will see the number of hours from the last resync which you can then examine either by looking at the appropriate hourly file or by dragging the active line backwards.
Remember not to disconnect the modem frequently and to switch off the power supply before making any changes.
Good luck and kind regards,
Walter
Edit to add:-
P.S. These suggestions are offered after my practical experiences of four or five years helping a community with many long poor lines as you will see if you explore the posts here.
I too have learnt a lot over this period.
There are certainly differences in the components in some filters which you will see discussed in this splendid forum. However, apart from actual faulty filters, I haven't seen any one type being significantly superior to others.
Similarly there are many different modems; although some will work better on a particular line, there will always be minor differences. My experiences on some very bad lines is that the 2Wire seems able to hold such lines in sync when others can't.
You will find there are many opinions here so perhaps some others will offer more suggestions ?
