The trigger-based replication concept is actually meant for SAP source systems. The main differences are as below :
a) There would be a database connection between non-SAP source and SLT system instead of RFC.
b) Source must have primary key c) Tables DD02L, DD02T which contains metadata are just initially loaded but not replicated.
d) The read modules resides on SLT system.
e) Tables with database specific formats may need transformation rules just before they are replicated.
f) Only SAP supported databases (with respective DBSL for SAP Net Weaver 7.02) are supported as non-SAP source systems.