ADTRAN user manual Configuring the ISU 512 for V.25 BIS IN-BAND Dialing

Chapter 5: Configuration

CONFIGURING THE ISU 512 FOR V.25 BIS IN-BAND DIALING

V.25 bis dialing is used primarily by data terminal equipment with synchro- nous interfaces (HDLC/SDLC or BSC/BISYNC) not supporting the AT com- mand set, which is commonly used by asynchronous devices. The ISU 512 supports V.25 bis in-band dialing in accordance with Fascicle VIII.I - V.25 bis (Malaga-Torremolinos 1984, Melbourne 1988).

Recommendation V.25 uses the following DCE/DTE control signals:

Transmitted data	Circuit 103
Received data	Circuit 104
Ready for sending	Circuit 106
Data set ready	Circuit 107
Data terminal ready	Circuit 108/2
Calling indicator	Circuit 125

The ISU 512 supports the following V.25 bis commands to control automatic calling and answering:

CRN	Call request (number in command)
CRS	Call request (using stored number)
PRN	Program stored number
RLN	List stored number
CIC	Connect incoming call
DIC	Disconnect incoming call

When using stored numbers, V.25 bis accesses stored numbers 1 through 9 used by front panel dialing. See Dialing Options (in this chapter).

Auto answer should be disabled if V.25 bis is in control of answering incoming calls with the CIC/DIC commands, since the other settings for Auto answer will override V.25 control of the answer function.

56 ISU 512 User Manual 61202.086L1-1