Cisco Internal VPN Service ModuleCisco Internal VPN Service Module The Cisco Internal VPN Service Module (VPN ISM) is a purpose built accelerator designed for Cisco Integrated Services Routers Generation 2 (ISR G2). It delivers a dramatic boost to VPN encrypted traffic by offloading the most resource intensive cryptographic operations from the host routers main processor. With a multicore processor that operates independently from the router, the VPN ISM provides scalable VPN