DB2 Connect cmallc rc=20

Franco Masone

DB2 Connect cmallc rc=20
Hi to all,
Db2connect again......
I am trying to do a connection with the OS390 DB2 V4.1, I try to use APPC
thru SNA SERVER (Independent LU 6.2).
I followed all the directions from the manual, at time of connection I
receive a message reporting a return code 20 (product specific error)
from cmallc.
Any suggest ? The 6.2 lu is defined in Sysibm.lunames.
How can I debug this (perhaps communication (CPI) problem ?)
Thanks in advance