Znyx Networks bh5700 manual Ethernet Switch Blade Users Guide Release 3.2.2j

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.

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