Ericsson ZAT 19.2 Operation Manual page 234

40.5 LPDA2 Command mode
LDPA2 (Link Problem Determination Aid) is a protocol defined by
IBM. This protocol uses SDLC frames inserted into the data stream
to give commands to the modem. In order to enable the modems to
accept LDPA2 commands, both network function and LPDA2
address must be configured.
10.5.1 Network function:
Primary : The modem accepts LPDA2 commands from both the
DTE side and the line side.
Secondary : The modem only accepts LPDA2 commands from
the line side.
10.5.2 LOPA2 Address:
Consult your network equipment documentation in order to
obtain the correct addresses. These may vary from one
manufacturer to another. The addresses in the examples are
often used in Eripax and IBM networks.
Example LPDA2 configurations:
Network Network
node node
Modem 1 Modem 2
Modem 1 Modem 2
LPDA2 Primary LPDA2 Primary
LPDA2 Address = 03 LPDA2 Address = 01
Both nodes may give LDPA2 commands to the modems.
10-6 LZTR104006 R1.00
Zat 14.4/14.4-7 and 19.2/49.2-7