Instruction manual

FEATURES AND SERVICES
Pause characters may be used consecutively if a longer pause is required. Note that System
25 cannot detect tones, such as a second dial tone for end-to-end signaling.
End-to-End Signaling:
Data connections to off-premises destinations require that a conversion resource (pooled
modem) be inserted into the connection.
Occasionally it is necessary to send additional
tones to the remote endpoint after the connection is established to signal the remote
equipment. A “mark” character ($) must be included on the DIAL: line to indicate to call
processing that the remaining digits are to be sent to the far end prior to insertion of the
conversion resource into the connection.
The “mark” character marks the boundary
between the digits dialed to reach a distant endpoint, and the digits used by that distant
endpoint after it has answered.
Pause characters may and usually should follow a “mark”
character. An example using a
“mark” character and several pause characters is shown
below. Dashes are included for readability.
Examples of dialing are as follows:
● DIAL: 3478
● DIAL: 9-1-(201)-946-8123,,$,5678
● DIAL: 9%946-8123%%$%5678%137%110
Call Disposition:
Call progress messages corresponding to call progress tones provided to voice terminals are
listed in Table 2-1. The message supplied (indicating reorder, busy, ringback) depends on the
disposition of the call.
1.
2.
3.
When ringback is received the displayed message is
“RINGING” (internal calls only).
For outside calls, the corresponding call progress message is
“DIALING . . . .”.
If the endpoint answers, the displayed message is
“ANSWERED” (internal calls only).
Then, if the handshake succeeds, a data connection is established. For outside calls,
when the system has finished dialing, the message “COMPLETED” is displayed.
If the handshake fails because a connection cannot be established between
endpoints (e.g., a port optioned at 9600 baud attempts to talk to a conversion
resource that can only talk at 300 or 1200 baud), the user receives “INCOMPATIBLE
FAR END,” “ DISCONNECTED,” and the data endpoint goes on-hook.
If the far end does not answer, the caller must press Break to terminate the call attempt.
If the disposition of the call is such that TRY AGAIN or BUSY (indicating reorder or intercept
and busy respectively) is received, the switch sends
“DISCONNECTED” to the data terminal
and returns the data endpoint to idle mode.
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