This is off-topic for Asterisk, but since echo problems with the
X100P cards seems to be a common issue and one which people blame on
telco loops, I'd suggest getting the following gear: a 3M Dynatel
subscriber loop test unit.
The 745 is the one I have experience with, and if you have a fairly
decent clue of what you're doing, you can test line silence,
resistance, voltages, polarity, etc. Well worth a few bucks. There
are other models of the Dynatel line, many of which are more complex
(and more expensive) but will tell you quite a bit about a copper
loop.
If you read this soon enough, you can bid on one right here (no, I'm
not selling it):
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2572083615&category=25418
JT
