Altera, Sarance join Cortina-Cisco coalition

COLORADO SPRINGS, Colo. — The Interlaken physical layer protocol developed by Cortina Systems Inc. and Cisco Systems Inc. has gained its first external partners: Altera Corp. will implement the protocol in its Stratix II GX FPGAs, assisted by communications IP core specialist Sarance Systems Inc.

Cisco, seeking an interconnect standard for 10- and 40-Gbit links based on the older SPI-4.2 standard, has been working closely with Cortina since 2003. Earlier this year, the partners introduced Interlaken as a royalty-free specification.

Jim McKeon, Cortina's product manager, said "the model was what Cisco had done with the S-GMII spec earlier. Rather than take it to a standards body, the key was to get an open protocol implemented quickly."

Cortina works on aggregation and interface ASSPs as well as control-plane processing from its acquisition of Azanda Network Systems Inc. When it introduced Interlaken in April, the effort was seen as a competitor to the Network Processing Forum's Scalable-SPI effort. NPF merged with the Optical Internetworking Forum (OIF), but Cortina and Cisco still chose not to submit Interlaken to the OIF.

Hence, the addition of Altera and Sarance gives the standard needed external viability.

Dave Ridgeway, strategic marketing manager of Altera's wireline business unit, said the interface can be implemented in 10-, 24-, and 40-Gbit/s implementations, varying only in the number of 6.375-Gbit/sec "lanes" and the size of lookup tables. Since the Interlaken data path standard can be used with a number of control plane protocols, including Ethernet, Sonet, PCI Express and Rapid IO, the protocol will not compete with other Layer 2 and 3 implementations.

Farhad Shafai, vice president of R&D at Sarance, said it develops higher-layer algorithmic search and traffic management cores, but also work with Altera on using the Stratix II's on-chip serdes blocks to connect with external interconnect. While there is no exclusivity arrangement between Altera and Sarance, Shafai claimed Stratix II is the only architecture capable of supporting Interlaken for Sarance's implementation.