[ale] Diagnostic help needed

[Drifter]

Abandoned Speakeasy and its DSL connection through Covad and AT&T.
Went with Comcast as the (slightly) lesser of evils -- the other being 
AT&T.
Comcast technician was scheduled to arrive between 9-11 am on Thursday.
He arrived at 10:55 and insisted he was on time.
I was not amused.
Technician did his job: installed a cable "modem" that provides internet 
and VOIP, thus allowing us to cut all our ties to Ma Bell.  When the 
installer left Thursday at 1 pm  Speed tests showed 20 mbs down and 3.7 
mbs up. Much better. :)  That was Thursday afternoon.

Friday morning a friend came over and helped me rewire the cat-5 cable as 
I needed to move the router down next to the cable "modem." (Friend is 
MUCH better at wiring new plugs on the end of cat-5 cable than I will ever 
be.)  When my friend left Friday afternoon a speed test still showed 
similar numbers throughout the house. All seemed good.

After lunch Friday I noticed that download speeds seemed to be lagging so 
I ran another test (using Speakeasy's test). Speeds had dropped to <3 
coming down but had increased to >4 going out.  WTF?  By Friday night 
download speeds had dropped to <2 and uploads were humming ~4.

I am clueless.  I whined and Comcast is sending out another technician 
late this afternoon.  Only guess I have is that the "modem" has a fubar 
component.

Thoughts would be appreciated.  It would be nice if I knew where to tell 
the Comcast guy where to look.

Sean