asterisk users - Sep 2008 - Newbie questions: seting up extension for miSDN

Hello!
   Sorry, I'm sure it's stupid. but I've got a simple ISDN line and
a simple
ISDN-card, now finally running. :-)
   I'm using application Jack and asterisk (CLI) only to do my bidding. Now
I
can make calls. But how ca I setup my extensions.conf to receive a call?
I've
had an example like tis:
[default]
exten => 500,1,Answer()
exten => 500,n,Jack()
   But it seems I can't do anything with me. Besides, the PortAudio (at
least I
assume) gives me some errors. Here's an example:
CLI > console dial 500 at default
[Sep  8 19:02:40]   --- <("<) --- Call from Console has been Answered
---
(>")>
---
[Sep  8 19:02:40] WARNING[7399]: chan_console.c:367 start_stream: Failed to 
open
  stream - (-9997) Invalid sample rate
CLI > P[ 1] MGMT: SSTATUS: L2_RELEASED
   Now if I can do it with application Jack, please anyone give me a pointer to 
the right doc or an example.
   But for the docs: Please give me an example for an "extension" that
is my
simple telephone. I have nothing fancy over here and I get confused. Sorry...
   Kindest regards
        Julien

--------
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