Product Announcement
7 April 2003
updated 10 December 2003

Myrinet Switch Line Cards with Gigabit-Ethernet Ports

Myricom is pleased to announce the first of a new class of Myrinet interoperability products. The M3-SW16-8E switch line card pictured above operates in Myrinet-2000 switch enclosures, and presents eight Gigabit-Ethernet (GbE) ports on the front panel.

This new product provides convenient, high-performance interoperability between Myrinet ethernet emulation (TCP/IP and UDP/IP over Myrinet) and native GbE. These Myrinet switch line cards can also be used to build economical, high-degree, cluster switches for GbE hosts.

The GbE ports of the M3-SW16-8E line card are 1000BASE-T on RJ-45 connectors for Cat-5 ethernet cables. The GbE ports are full-duplex only and Gigabit-ethernet only. There is no half-duplex mode of operation nor speed negotiation to 100BASE-T or 10BASE-T. The line card includes a 16-port Myrinet switch with 8 Myrinet System Area Network links on the connector to the backplane.

The conversion between ethernet-emulation packets on a Myrinet and GbE packets is accomplished by a Lanai-XM chip on each GbE port. The physical-level conversion is a feature of the multiprotocol port of the Lanai XM. The data-link-level conversion is accomplished by firmware that executes on the RISC inside the Lanai XM. The protocol-conversion firmware is loaded into the memories of the Lanai-XM chips during the line-card initialization. This firmware can be upgraded through an M3-M monitoring line card. In addition to its protocol-conversion functions, the firmware participates in Myrinet mapping.

For interoperability with Myrinet mapping and ethernet emulation, the firmware for M3-SW16-8E line cards requires that hosts use GM 2.0.9 or later, or MX. Cluster switches with only GbE ports are allowed; the Myrinet mapping is performed between the Lanai-XM end points. The current (version 1.1) firmware supports all mandatory requirements for GbE MAC bridges, i.e., the GbE ports may be connected either to GbE hosts or to other GbE switches.

Performance. The GbE ports operate at the full 1+1 Gb/s data rate of GbE. The protocol processing in the Lanai-XM requires ~3.3µs per packet, thus allowing on each port ~300K packets per second in the sum of both directions. Just as Myrinet ethernet emulation allows 9KB "jumbo frames," the protocol conversion provided by the M3-SW16-8E firmware allows jumbo frames on the ethernet.

Inasmuch as the Myrinet fabric within the switch operates at 2+2 Gb/s full-duplex, twice the data rate on the full-duplex GbE links, the maximal load on a full-bisection Myrinet network from the GbE ports is 50%, a condition under which there is little blocking.

GbE Flow Control. A Lanai-XM-based GbE MAC bridge has 128KB of input buffer and 512KB of output buffer on each port. The GbE ports of the line card support flow control. When the physical GbE link connection is established, the GbE ports auto-negotiate the GbE flow control, either symmetric (in which both ends of a link can stop each other), asymmetric (in which only one end can stop the other), or none.

Price & Availability. The list price of the M3-SW16-8E component is $3,200. Specifications can be found here.

7 April 2003, updated 10 December 2003