BIT SWITCHES
21 December, 2001
3-58
G4 Internal Switch 16: D channel layer 3 (Approval)
No.
FUNCTION
COMMENTS
7
Transfer capabilities (SI) informed
in 1TR6 ISDN G3 transmission
0:
G3 Fax
1:
Analog
This bit determines whether transfer
capabilities informed in the Service Indicator
for 1TR6 ISDN G3 transmission. This switch is
effective in coping with communication
problems with some types of T/A and PBXs.
Normally keep this bit at 1 in Germany 1TR6.
G4 Internal Switch 17: CPS Code Used for G4 to G3 Fallback - 1
No.
FUNCTION
COMMENTS
0
to
6
Condition for fallback from G4 to G3
Bits 0 to 6 of bit switch 17 contain a CPS code, and bits 0 to 6 of bit switch 18
contain another CPS code. If a CPS code is received which is the same as either of
these, communication will fall back from ISDN G4 mode to ISDN G3 mode.
The CPS codes must be the same as those specified in table 4-13 of ITU-T
recommendation Q.931.
Examples: Bit 6
5
4
3
2
1
0
1
0
0
0
0
0
1
CPS code 65
1
0
1
1
0
0
0
CPS code 88
For the codes in bits 0 to 6 of bit switches 17 and 18 to be recognized, bit 7 of bit
switch 17 must be 1. Also, bit 0 of the Communication Switch 07 must be at 0, or
Fallback from G4 to G3 will be disabled.
7
This bit determines whether fallback from G4 to G3 occurs on receipt of one of the
CPS codes programmed in bit switch 17 or 18, or on receipt of a certain standard
code.
0:
Fallback occurs on receipt of any of the following CPS codes:
Universal (Euro ISDN) - #3, #18, #57, #58, # 63, # 65, #79, #88, and #127
Germany 1TR6 mode - #3, #53, #58, and #90
Others - #3, #65, and #88
1:
Fallback from G4 to G3 occurs on receipt any of above CPS codes or one of the
CPS codes programmed in bit switch 17, 18, 1A, 1B, or 1C
G4 Internal Switch 18: CPS Code Used for G4 to G3 Fallback - 2
No.
FUNCTION
COMMENTS
0
to
6
Condition for fallback from G4 to G3
See the explanation for bits 0 to 6 of bit switch 17
7
This bit helps to choose the CPS code set for G4 to G3 fallback.
0:
Fallback occurs on receipt of the CPS code set, which is specified by the country
code setting.
1:
Fallback occurs on receipt of the Universal CPS code set (#3, #18, #57, #58, #
63, # 65, #79, #88, and #127) even if another country code is programmed.
If bit switch 17 bit 7 is “1”, fallback occurs on receipt of the Universal CPS code
set or one of the CPS codes programmed in bit switches 17, 18, 1A, 1B, or 1C.
