8 architecture
The Pica8 architecture features a patented, distributed, full-duplex forwarding engine architecture (“808/2SB”) that provides lossless forwarding of frames and traffic. This architecture is designed to enable high-bandwidth, low-latency forwarding, enabling resilient Level-3 routing, data-plane L2VPN, and multicast applications. The 8082/SB architecture works by having the packet-forwarding engine split into two identical parts, each referred to as a side buffer (“SB”). Each SB contains a lookup table and a small buffer that allows the forwarding engine to store incoming or outgoing packets prior to forwarding them. The lookup tables of the two SBs are kept synchronized using a distributed protocol, and policers for each SB enforce bandwidth limits for each port. The distributed processing in the forwarding engine allows for efficient redundancy between the two SBs, providing high resiliency and failover when one SB crashes or becomes unresponsive. As an added benefit, this architecture provides a buffer at the packet level to absorb packet bursts, increasing throughput and reducing packet-dropping.