7.3.5. Configuring a HG 3500 on the LAN Segment 
The HG 3500 module (STMI2/4 and STMIX/STMIY) establishes the payload connections
between the central OpenScape 4000 system and the OpenScape 4000 LAN
segment.
- HG 3500 boards may be implemented both in peripheral shelves (LTU 1-15) in the central system and in access points (LTU 17-99). You can implement the same number of HG 3500 gateways that you configured with the AMO DIMSU (see Section 3.4.2, “Number of Internal HG 3500 Gateways in a System”, on page 546).
- Multiple HG 3500 modules can be implemented in an OpenScape 4000 system.
- All HG 3500 modules must be connected at the OpenScape 4000 LAN segment.
- The HG 3500 hardware is the STMI2/4 board. This board can simultaneously offer IP trunking, a WAML circuit, IPDA function, HFA function and SIP subscriber function. The type and number of circuits or B channels available in each case is set with the AMO BFDAT.
INFO:
It is not possible to configure WAML on STMIX/STMIY.
An OpenScape 4000 LAN segment is that part of the customer network
where the central system’s IP components and directly connected (that
is, not via router) access points are installed.