Znyx Networks bh5700 - Manual (Page 21)

network-enabled Linux implementation.
The purpose of the routing table is to tell the packet forwarding software where to forward the
data packets. In Linux, the packet-forwarding algorithm is operated in software. Normally, the
routing tables are maintained by operator configuration and the various routing protocols that run
in the application environment of Linux.
OpenArchitect uses an innovative new approach for forwarding packets. It provides embedded
software daemons that replicate ( shadow) the Linux routing tables in the silicon-based
forwarding tables (see Figure 1.1: Fabric Switch Elements). In the OpenArchitect switching
environment, the switching chips do the real-time work in switching network packets. The switch
fabric consults its own forwarding tables for each incoming packet; and either filters or forwards
the packet to any egress port, the embedded CPU, or to any combination. The Linux routing
tables, running in software, are used to update the silicon-based tables. This provides both the
flexibility and control of the Linux software environment and the speed of dedicated switching
silicon.
The OpenArchitect environment includes additional features. For example, installing the
OpenArchitect switch gives you immediate implementation of Linux routing protocols. Also, you
have complete support of routing table updates and a standardized method for configuration.
Finally, you can quickly integrate bug fixes, protocol enhancements and additional protocol
implementations from the Linux community. You can also integrate OpenArchitect into other
Linux applications including VPN software, voice over IP protocols, Quality of Service, and
HTML configuration.
RAIN Management API (RMAPI) is a generic interface for passing control data. The
OpenArchitect libraries are implemented completely above RMAPI. The libraries provide a front-
end to RMAPI to simplify application writing. Currently one library is implemented, a general
library called zlxlib. As the OpenArchitect application requirements grow, the existing library
will be expanded and additional libraries will be created.
Ethernet Switch Blade User's Guide release 3.2.2j page 21