Woven Systems looks to trump 10G Ethernet switches

New 144-port switch said to provide the highest port density and capacity in the industry

Start-up Woven Systems this week is expected to launch its 10G Ethernet data centre switch -- a box the company says one-ups the switching power of Cisco, Force10 Networks and Foundy Network 10G gear and matches the low-latency performance of Fibre Channel and Infiniband with lower-cost Ethernet technology.

At 144 non-blocking 10G Ethernet ports, Woven says its EFX 1000 switch provides the highest port density and capacity in the industry. The switch includes low-latency packet processors and congestion-detection mechanisms, which mimic Fibre Channel or Infiniband performance but with less cost and better manageability, Woven says. As many as 4,000 of the 10G switch ports can be configured as a single virtual switch, or fabric, for connecting servers, storage and other network devices in a data centre at very high speeds.

The 12-slot EFX 1000 chassis uses 12-port 10GBase-CX4 Ethernet line cards and has a redundant backplane with a capacity of 2.8Tbps to allow every port on the switch to run at line-rate. Speeds and feeds aside, Woven says the key to its product is its vSCALE packet processors -- three on each blade -- which allow the boxes to connect as a fully redundant, multipath mesh while using standard Layer 2 Ethernet technology.

This setup differs from standard Layer 2 networks, where Spanning Tree Protocol closes off all but the primary uplink path of a LAN switch, only activating the alternate paths when the links fails -- a process that can take up to a half-second or more.

Woven Systems says its technology allows a switch to have multiple paths to other switches in the network that are always active and can move traffic among any other switches in the mesh. The multipath Layer 2 network also allows for near-instantaneous failover of network connections to alternate paths, with switchover time in the sub-10-microsecond range (10Â millionths of a second). Traffic latency from port-to-port inside a system measures around 1.5 microseconds, and latency among interconnected Woven switches is around 4 microseconds. The company says this low-latency performance of its switches is on par with other high-speed/low-latency interconnect technologies, such as Infiniband, Myrinet or Fibre Channel.

The vSCALE packet processors analyze Layer 4 traffic flow -- TCP/UDP port data in packets --- and measure traffic congestion and link integrity based on the flows they observe. If the switch detects high utilization on one uplink port, the switch moves the flow to another live port. Switches connected in this fabric insert traffic measurement bits into every Ethernet frame moved by the Woven switches. (The time-stamped data goes into the extra space of the virtual LAN [VLAN] tag frame space). For every hundredth Ethernet frame transmitted, this time-stamped data is pulled from a random packet and sent back to downstream switches to give the devices data about latency and congestion on the network. The downstream switches use this information to make Layer 4 load-balancing decisions across the multiple paths to which they are connected.

This approach "is an adaptation of flow-based traffic forwarding," says Joe Skorupa, a research vice president at Gartner. "Similar to Layer 3 networks, but they're doing it in a very innovative way down at the Layer 2 level." Layer 2 multipath switching allows for much quicker packet processing than Layer 3 routing protocols, such as OSPF, EIGRP or RIP.

"Doing all the switching at L2, [Woven] can use commodity Ethernet switch chips," Skorupa says, which make the products less expensive than Layer 3 gear.

To create the multilink mesh, the Woven vSCALE processors play a trick on standard Layer 2 VLAN, spanning tree and MAC addressing technologies. The Woven switches establish multiple Layer 2 VLAN connections among other switches in the mesh. For every link to another switch in the mesh, media access control (MAC)Â addresses of Ethernet frames on the switch (which are associated with the VLANs) are encapsulated inside other Ethernet MAC addresses. This method invokes multiple instances of Spanning Tree (one instance per encapsulated MAC/VLAN association). The result is that switches can send traffic down various multiple paths very quickly, simply by changing a bit in the MAC/VLAN association in frame headers.

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Woven says this model can be used to create an Ethernet fabric with as many as 4,000 10G Ethernet ports. Switches in the fabric auto-discover each other when plugged in. A Woven Dashboard network management tool can be used to partition sections of the fabric for certain types of dedicated traffic, such as IP storage traffic, application traffic or other flow types. The Dashboard also provides visual health-checking graphs to show latency and congestion areas in the fabric, and at certain chassis and ports in the configuration.

Woven is introducing the EFX 1000 with all-copper 10G Ethernet ports, based on the 10GBase-CX4 standard. These ports use Infiniband-style copper cabling, targeting short (less than 100 feet) switch-to-switch or switch-to-server links in the data centre. Initial pricing will be around $US1,500 per 10G Ethernet port. The vendor plans to announce fibre-based port modules later this year. By the end of 2007, modules with 10GBase-T (10G Ethernet over Category 5/6 wiring) are expected.

Woven Systems was co-founded in 2003 by Dan Maltbie, now chief product officer, who is a veteran of Fibre Channel vendor McData and HP and is active in IEEE Ethernet standards. The other founder, Bert Tanaka, CTO, was a chief scientist for satellite technology at Boeing and a veteran of Newbridge Networks. Woven CEO Harry Quackenboss's experience includes being vice president at switch vendor Crescendo Communications when it was acquired by Cisco. Woven received $US10 million in funding from Goldman Sachs and Palomar Ventures in 2005.

Woven will compete with established core Ethernet switches, such Foundry's BigIron RX, Cisco's Catalyst 6500, Extreme's BlackDiamond 10K and Force10's ER1200 series. However, analysts say the start-up will see more of a challenge from an assortment of other start-ups focused on the emerging data centre network area -- some with significant backers.

A potential Woven Systems foe already with industry buzz and built-in clout is Nuova Systems, the Cisco-backed data center network start-up founded by former top technologists from Cisco, including Mario Mazzola, Luca Cafiero, Prem Jain and Soni Jiandini.

Industry watchers say Nuova is working on a box that combines Ethernet, Fibre Channel and Infiniband switching with technologies such as remote direct memory access, a high-speed input/output technology, and server virtualization.

Other potential rivals for Woven include Teak Technologies, which is building multi-protocol data centre network gear based on IBM's BladeCenter technology. This company also has Cisco ties, with investments from the network vendor. In addition, a top Cisco routing engineer is a technical advisor to the company.