FPGAs positioned for 100G OTN, Ethernet designs

Having been shut out of the high-end action in the coherent end of 100 Gbps, Altera (Nasdaq: ALTR) and Xilinx (NASDAQ: XLNX) have moved to position their field programmable gate arrays (FPGAs) as viable options when Optical Transport Network (OTN) and Gigabit Ethernet designs move to 100 Gbps.

Having been shut out of the high-end action in the coherent end of 100 Gbps, Altera (Nasdaq: ALTR) and Xilinx (NASDAQ: XLNX) have moved to position their field programmable gate arrays (FPGAs) as viable options when Optical Transport Network (OTN) and Gigabit Ethernet designs move to 100 Gbps. The two silicon merchants have beefed up their FPGA capabilities and positioned themselves as “one-stop shops” through the acquisition of relevant intellectual property (IP) suppliers. The result is that both companies can offer worthy alternatives to ASICs or application-specific standard products (ASSPs) for high-speed Ethernet and OTN applications. But finding a good independent supplier of IP might be a challenge for designers disinclined to use their FPGA supplier’s cores.

Big steps, in a hurry

Xilinx has proven the most aggressive FPGA supplier when it comes to 100-Gbps. In March 2011, the company announced its roadmap for support of FPGA-based line card designs for both 100-Gbps and eventual 400-Gbps OTN applications. The roadmap consisted of new Virtex-6 HXT FPGA capabilities for 100-Gbps OTU4 OTN designs, easier transition from the 40-nm Virtex-6 to the more capable 28-nm Virtex-7 for 400G OTN and beyond, and an upgrade of its in-house OTN expertise through the acquisition of UK intellectual property house Omiino (see "New Virtex-6 capabilities, Omiino acquisition point Xilinx toward 400G OTN FPGA support").

The new capabilities will be offered initially in the form of the OTN Targeted Design Platform, Xilinx said. The kit, which sells for about $25,000 without optical modules, includes a Virtex-6 HXT FPGA development board with pre-defined and implemented reference designs for such OTN applications as 100G ODU switching, 100G Ethernet to OTU4 transponders, and 10x10 to OTU4 transponders. The OTN platform also leverages IP from the former Omiino, including 100G MuxSAR capabilities.

Typically, two Virtex-6 FPGAs will be required for 100-Gbps transponders and 10x10 over OTU4 muxSAR designs, Gilles Garcia, director of the Wired Communication Business Unit at Xilinx, told Lightwave at the time of the announcement. The same designs could be completed with a single chip using the Virtex-7 – when it becomes available in 2012. Garcia says that several companies have already begun working with the two-chip Virtex-6 approach to speed time to market.

Two months later, in May 2011, Xilinx further expanded its in-house OTN capabilities via the acquisition of Modelware, a provider of traffic management/packet processing silicon IP cores. Not surprisingly, Xilinx also announced FPGA-based 100-Gbps traffic management reference designs based on its Virtex-6 HTX FPGA (see "Xilinx buys IP vendor Modelware for 100G traffic management").

While Garcia told Lightwave that he expects the Modelware IP to have a variety of applications, including PON aggregation and data center equipment, he saw the greatest opportunity in packet-optical transport systems – which naturally can be expected to require OTN and Ethernet support.

Finally, Xilinx capped its shopping spree with the acquisition of Sarance Technologies (see "Xilinx acquires Sarance Technologies to cap high-speed IP core shopping spree"). Sarance had been a longstanding IP core partner with Xilinx focusing on Ethernet MACs, Interlaken, and high-speed bridging support.

Xilinx clearly hopes counter those of its main competitor. Altera staked its claim to the high-speed OTN and Ethernet space before Xilinx’s Omiino announcement when it acquired IP supplier Avalon Microelectronics in December 2010 (see "Altera acquires OTN IP vendor Avalon Microelectronics"). The two companies already had a close relationship, as Avalon was the exclusive supplier of 100-Gbps OTN cores for Altera. Those cores typically found their way onto Altera’s Stratix V GX, Stratix V GS, Stratix V GT, and Stratix IV GT FPGAs.

Avalon, now Altera’s Newfoundland Technology Centre, supplied IP for both FPGAs and ASSPs, and also offered FPGA-based standard products via its V-ASSP (for “virtual ASSP”) line. Its Zenobia 100-Gbps IP portfolio included both OTN OTU4 and Ethernet capabilities:

  • 100G transponder/muxponder
  • OTU4/100GE client over OTU4
  • 100GE MLD
  • 100G GFEC
  • 100G EFEC
  • SFI-S interface
  • OTL4.10 interface
  • GFP
  • SAR.

Sorting through the 100G IP options

Needless to say, each FPGA supplier believes it offers a better product. Altera called Avalon the OTN and Ethernet leader among independent IP houses (including Omiino) when it acquired the company. Xilix’s Garcia, meanwhile, suggested to Lightwave that Omiino’s exclusive focus on IP for FPGAs versus the dual-use nature of Avalon’s IP made Omiino a more seamless fit in FPGA applications – an assertion a Newfoundland Technology Centre executive waved off when asked about it a OFC/NFOEC in March 2011.

But if you’re looking at using FPGAs in your high-speed OTN or Ethernet design, what other IP core options are there besides rolling your own? One perhaps unlikely source would be an ASSP vendor. AppliedMicro (Nasdaq:AMCC) actually started the run on OTN/Ethernet IP companies when it bought TPACK A/S of Copenhagen, Denmark, in August 2010 (see "AppliedMicro to acquire FPGA IP company TPACK to pursue OTN biz"). Like Avalon Microelectronics, TPACK offered both IP and Altera FPGA-based standard products, including (but not limited to) OTN devices. These “SoftSilicon” products included the P-OCKET series of OTN mappers, including add/drop muxes, as well as OTN switches.

But AppliedMicro doesn’t appear to be in the IP core market, preferring to leverage the TPACK technology for its own versions of the SoftSilicon products, including the TPOT414 and TPOT424 OTU4 transponders for OTU4 and 100 Gigabit Ethernet clients. If you’re just looking for IP, there are some outlets. One is Sembarc, whose Goliath transponder cores include the C series. The series comprises the Goliath_CE_CO 100GbE to OTU-4 core and the Goliath_CO_CO OTU-4 to OTU-4 regen core, as well as Sembarc’s muxponder cores, the Goliath_10XE_CO 10x10GbE to OTU-4 and the Goliath_80IE_CO 80x1GbE to OTU-4 cores.

Meanwhile, Aliathon Ltd. of Scotland offers cores for such 100-Gbps applications as transponders, 10x10G multi-protocol muxponders, add/drop multiplexers, repeaters, and ODUmuxes.

Finally, Xelic Inc. has 40-Gbps cores in its portfolio and undoubtedly has high-speed technology in development.

Which is not a lot of choice, but what’s left after silicon vendors have opened their wallets in hopes that their 100-Gbps customers will do the same.

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