ISDN Demonstrator User’s Manual
40-400-00011, Rev. B
27
The switch broadcasts a corresponding SETUP message to the line
associated with the dialed number, selecting a B Channel if one is available.
Any terminals that match the requested Bearer Capability, and optionally,
match the address contained in an Endpoint ID, respond to the SETUP with
an ALERTing message and begin ringing. When the switch sends an idle
Call Appearance to terminals that support the CACH option, the incoming call
is also indicated visually.
After the switch receives User 2 terminal’s ALERTing message, it sends a
corresponding ALERTing message to User 1 with Signal=Ring Tone.
When User 2 picks up the handset, the terminal sends the switch a
CONNect message, indicating the selected channel. The switch returns a
CONNect ACKnowledge, and completes a B Channel circuit between the
switch and User 2. It then sends a CONNect message to User 1, and
completes the B Channel circuit end-to-end. User Application-specific traffic
may now be exchanged over the B Channel.
When User 2 replaces the handset, the terminal sends a DISConnect
message. The switch removes the B Channel circuit and returns a RELease
message. It sends a corresponding DISConnect message to User 1, who
returns a RELease message. The switch sends RELease COMPlete to User
2, while User 1 sends RELease COmplete to the switch, ending the call and
releasing all allocated resources.
EXT Clock
IN
Connected from the "EXT CLOCK OUT" of another Teltone
ISDN Simulator for bonding b Channels.
OUT
Connect to the "EXT CLOCK IN" of another Teltone ISDN
Simulator for bonding B channels.
Troubleshooting
Physical Interface
Problem:
U-SYNC LED does not light.
Solution:
Ensure that the device is connected to the U interface and is
2B1Q encoded.
Solution:
Ensure that the U interface is terminated into the NT side of an
NT-1 or TE.
Solution:
Ensure that the terminating device (TE or NT-1) is receiving
power.
Solution:
Ensure that the loop length between the ISDN Demonstrator and
the terminating device is no longer than 1,600 meters.
