# Unified ISSU Platform Considerations

Unified ISSU is supported on E120 and E320 routers. Unified ISSU is also supported on the ERX1440 router with the SRP-40G PLUS with 2GB of memory. Unified ISSU on the ERX1440 requires a license key.

For information about modules supported on E120 and E320 routers:

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

For information about modules supported on the ERX1440 router:

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

Redundant SRP modules are required for unified ISSU support.

Unified ISSU is not supported on the ERX7xx models, the ERX1410 router, and the ERX310 router.