The AA MS-ISA2 is supported on IOM3-XP and on the IOM4-e. The MS-ISM versions contain one or two ISA2s embedded on a IMM card.
Each IOM can support a maximum of two AA ISA2 modules. To maximize AA ISA redundancy, deployment of AA ISAs on separate host IOMs is recommended as it provides IOM resilience. Traffic from any supported IOM (for example, IOM3-XP, a fixed port IOM (IMM)) can be diverted to an AA ISA host IOM.
The MS-ISA2 is field replaceable and supports hot insertion and removal. An SR system can support up to 15 active ISA2s for AA, each providing up to 40 Gb/s processing and 600 Gb/s total per system.
AA ISA software upgrades are part of the ISSU functionality. Upgrades to AA ISA software, for example to activate new protocol signatures, do not impact the second MDA slot for the IOM carrying the AA ISA, nor do upgrades impact the router itself (for example a new AA ISA software image can be downloaded without a need to upgrade other software images).