Mini Accelerator Cards (Macs); How Macs Work - Allied Telesis AR Series Hardware Reference Manual

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Mini Accelerator Cards (MACs)

Mini Accelerator Cards (MACs) provide additional processing features or
performance, but do not add extra physical interfaces to the router. A MAC can
be installed in the dedicated MAC slot (labelled Coprocessor Interface) on all
AR300 Series, AR400 Series, and AR720/AR740 routers.
MACs should only be installed by authorised service personnel. Unauthorised
opening of the router lid may cause danger of injury from electric shock, damage
to the router, and invalidation of the product warranty.
Three MACs are available:
AT-AR010 EMAC, Encryption MAC.
AT-AR011 V2 ECMAC, Encryption/Compression MAC.
AT-AR012 CMAC, Compression MAC.
See "Restricted Procedures" on page 93 for more information on the MAC
installation procedure.

How MACs work

MACs provide AR routers with high performance hardware-based encryption
and/or compression services. MACs have a DMA slave processor, which
operates independently of the base system. This processor is responsible for
the transfer of data between the base system and the MAC, and the control of
local high speed encryption and compression data processing devices.
This architecture allows data encoding to be performed off-line without
involving the base router processor in the process, thereby maximising MAC
performance while at the same time minimising impact on the router.
The MAC is a single card. Figure 26 on page 58 shows the layout of the board
for the AT-AR011 V2 ECMAC.
Figure 26: Location of main components on the AT-AR011 V2 ECMAC.
MAC CARD CONNECTOR
AR Router
CEMACCPU
C613-03031-01 REV E