ISDN Line Simulator User’s Manual
40-400-00012, Rev. E
28
When User 1 picks up the handset, the terminal sends a SETUP message to
the switch indicating the Off Hook condition (Switchhook), type of call (Bearer
Capability), the desired channel (Channel ID), the selected Call Appearance,
and the Calling Party Number.
The Called Party Number is not included, so the switch returns a SETUP
ACKnowledge message indicating the assigned channel and in-band tones
applied (Signal=Dial Tone). User 1 dials the number, which is sent in seven
consecutive INFOrmation messages (overlap send). Once the switch
determines that a valid number has been requested, it returns a CALL
PROCeeding message, which may include Display Text, showing the name
and requested number.
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.
NOTE: Contact Teltone for details regards bonding of B channels.