Meanings and Values of PSTN
Parameters Defined in Class 13

: If parameter 19 (modem initialization chain number) is k, enter the useful chain for the modem in class 20, recurrence 0, Parameter k-1).
: The X.25 address of line 2 is defined in class 22, recurrence 0, parameter i; to access FastPad (2), enter the telephone number, class 22, recurrence 1, parameter i and the XID frame number j to the programmed one with profile 42 in class 22, recurrence 2, parameter i. This XID frame is described in class 21, recurrence j-1.

On FastPad (2) side:

Line 5 is used as PSTN back-up line.

Programming of line No. 5:

class 12, recurrence 5: profile 41, i.e. DCE, PSTN back-up with modem V.25bis
class 13, recurrence 5: profile 43, i.e. PSTN back-up with modem V.25bis, EBS+XID.

Table D-1: Synchronous Connection Parameters

NUMBERS OF PARAMETERS SYNCHRONOUS CONNECTION

0

1

2

3

4

5

6

7

8

9

10

11

12

13

Profile number (see Appendix A)

Asynchronous protocol type in command mode

Call mode (108/1, 108/2)

Supervision time-out (switched link establishment)

Inactivity time-out

Modem bit rate

Time-out monitoring a dial attempt on PSTN

Number of dial attempts

Type of input/output

Number of modem initialization strings

XID transmit

XID receive

Number of attempts by remote party

Step of inactivity time-out

Parameter 1

Meaning:

Asynchronous protocol type in command mode.

Possible values:

0 =	reserved
1 =	V.25bis asynchronous
2 =	Hayes.

Parameter 2

Meaning:

Call mode.

Possible values:

1 =	direct (108/1)
2 =	addressed (108/2) (by default).

Note - In direct mode, the telephone number to dial is stored in the modem.
-In address mode, the switching equipment supplies the telephone number.

Parameter 3

Meaning:

Supervision time-out (switched link establishment).

Possible values:

1 to 250 (steps of 1 sec).

Default value: 180.

This time-out is activated when the first call packet is on the PSTN line. It is inactivated when the statistics function notices that the line is in service. When the time-out expires, the call is cleared.

Parameter 4

Meaning:

Inactivity time-out of the switched connection.

Possible values:

0 to 25. (Steps of 10 sec.).

Default value: 10.

This time-out is activated when there are no virtual circuits used on a line. When the time-out expires and there are still no virtual circuits used, the line is taken down. In case a virtual circuit has been opened, the monitoring time continues for 1 second.

Value 0 means that this mechanism is not activated. This time-out is not taken into account on level 2 disconnect request.

Parameter 5

Meaning:

Modem bit rate.

Possible values:

0	=	150	bit/s	4	=	2400	bit/s
1	=	300	bit/s	8	=	4800	bit/s
2	=	600	bit/s	10	=	9600	bit/s
3	=	1200	bit/s	11	=	19200	bit/s.

Default value: 10.

The other characteristics of the dialogue are:

without parity
1stop bit
8 bits per character.

The speed of the dialogue depends on the type of modem configured with parameter 1.

Parameter 6

Meaning:

Time-out monitoring a dial attempt on the PSTN.

Possible values:

0 to 250 (unit = 10 s).

Default value: 3.

This time-out is activated at each PSTN dial attempt. It is inactivated when the connection is established or when a modem error message is received. When the time-out expires, a new dial attempt is made after a time-out of 30 s.

Note The number of dial attempts multiplied by this time-out plus 30 seconds should not exceed the value of parameter 3. If this is the case, the switched link is inactivated when the time-out of parameter 3 expires.

Parameter 7

Meaning:

Number of dial attempts.

Possible values:

0 to 250.

Default value: 3.

Parameter 8

Meaning:

Type of input/output

EBS: synchronous standardized input (DCE defined P1 C12)

SBS: synchronous standardized output (DTE defined P1 C12).

Possible values:

00 =	EBS/SBS
01 =	EBS
02 =	SBS.

The EBS/SBS mode is not authorized in 108/1.

Parameter 9

Meaning:

Number of modem initialization strings (see C20-R0).

Possible values:

0 =	no string
1 to 3 =	parameter of recurrence 0.

Default value: 1.

This string is used to initialize the modem in Hayes mode. It is optional and it detects the presence of the modem in V.25bis mode.

Parameter 10

Meaning:

Transmit of XID frame.

Possible values:

108/1 mode:	0	= no.
	1 to 4	= no of frame to be transmitted (C21).
108/2 mode:	0	= no.
	1	= yes.

Parameter 11

Meaning:

Receive of XID frame.

Possible values:

0 = no

1 = yes.

Parameter 12

Meaning:

Number of attempts by remote party (transmit of XID frame).

Possible values:

0 to 250.

Parameter 13

Meaning:

Step of inactivity time-out

Possible values:

0 = step of 1 s

1 = step of 10 s.

Table of Contents