# Platform Considerations

For information about modules that support L2TP and IP tunnels with IPSec on the ERX7xx models, ERX14xx models, and the ERX310 Broadband Services Router:

- See LNS and LAC support in ERX Module Guide, Table 1, Module Combinations for detailed module specifications.
- See LNS and LAC support in ERX Module Guide, Appendix A, Module Protocol Support for information about the modules that support LNS and LAC.

For information about modules that support L2TP and IP tunnels with IPSec on the E120 and E320 Broadband Services Routers:

- See LNS and LAC support in E120 and E320 Module Guide, Table 1, Modules and IOAs for detailed module specifications.
- See LNS and LAC support in E120 and E320 Module Guide, Appendix A, IOA Protocol Support for information about the modules that support LNS and LAC.

## Module Requirements

To create IPSec-secured tunnels, you must install an IPSec Service module (ISM) in the ERX router. The ISM is a security gateway and functions as one of the endpoints for secure tunnels. The tunnel endpoints are the tunnel source and the tunnel destination IP addresses. For an L2TP/IPSec tunnel, the source is the L2TP network server (LNS) and the destination is the L2TP access concentrator (LAC).

For information about installing ISMs in the ERX routers, see the ERX Hardware Guide.