Sahasra 50000

• High density, low power, embedded-SRAM-based NSE for longest-prefix matching and exact matching applications
• High entry capacity
   -Sahasra 51500: 1.5M IPv4 route entries in application worst-case
   -Sahasra 50650: 650K IPv4 route entries in application worst-case
   -Capacity scales approximately linearly with entry width
   -Gluelessly depth-cascadable up to seven devices (up to four devices with no loss of throughput) for increased capacity
• High search performance
   -Fully deterministic worst-case performance
   -250-MSPS throughput for up to 72-bit wide routes
   -125 MSPS for 144-bit lookups; 62.5 MSPS for 288-bit lookups
   -Fixed latency of 54 cycles (at 250 MHz) for all key sizes
• Low power
   -Typical power of 6W in Sahasra 51500 and 4.5W in the Sahasra 50650 device at 250 MSPS
   -Lookup stages activated only as required
   -Each cascaded device only consumes 3.5W additional power for search keys up to 144 bits
   -1.2V core
• High search flexibility
   -Supports key/entry widths up to 288 bits
   -Concurrent support for multiple tables such as IPv4 unicast/multicast, IPv6 unicast/multicast, VPN, MPLS, MPLSVPN
   or VRF, Ethernet, Microflow labels and similar table types
   -Fine storage granularity for efficient mixing of routes
• Easy table management
   -Route updates performed by stealing a small percentage of search cycles
   -Table space dynamically shareable
   -Only 1% of cycles are stolen in worst-case per thousand updates per second
• Error management
   -Built-in hardware error correction (2-bit detect, 1-bit correct) for lookup pipeline
   -Parity data protection on search interface
• Parallel point-to-point interface
   -High-speed DDR signaling
   -Electrically compatible with Ayama™ 10000 NSE family
• Support for LA-1 NPUs
   -Connect to 2 LA-1 NPUs through Ayama 20000 device
• Small package footprint
   -25 x 25 mm Flip chip BGA with 1.27-mm ball pitch

Routers in the Internet today use a database of prefixes to make forwarding decisions on packets. A router searches the entries in the prefix database, using parts of the packet-header (for example, the destination address of the packet) as the search key. The search that routers have to perform in the prefix database is a longest-matching prefix search. The Sahasra 50000 performs very high-speed longest-matching prefix searches, while supporting a large number of prefixes and allowing fast updates. In particular, up to 1.5 million IPv4 prefixes (in the Sahasra 51500) are supported even in the application worst case, with a lookup rate of 250 MSPS. Furthermore, the Sahasra 50000 allows the on-chip table space to be dynamically shared by tables corresponding to various protocols such as IPv4 unicast, IPv6 unicast, IPv4 multicast, IPv6 multicast, Ethernet and MPLS-VPN.