Myrinet [Myricom, Inc.]

Myrinet is a Gigabit-per-second local-area network (LAN) based on thetechnology used for communications and packet switching in MPPsupercomputers.A Myrinet LAN is composed of host interfaces, switches, and links. Themultiple-port switches may be connected by links to other switches or tothe single-port host interfaces in any topology. Unlike FDDI andEthernet, which share a fixed bandwidth among all clients, the aggregatebandwidth of Myrinet scales with the configuration.A Myrinet link is a full-duplex pair of cahnnels, each of which opeatesat at data rate of 0.64 Gb/s (Gigabits per second), or an aggregate datarate for the full-duplex link of 1.28 Gb/s. The link is physically aflexible, 0.4-inch-diameter, UL-Listed Type CL2, shielded, multiconductorcable. The maximum length of these electrical-cable links is 25m (82feet); however, switches and cable repeaters allow the diameter of thenetwork to be arbitrarily large. Adapters for optical-fiber links up to2Km (1.2 miles) in length are in development. The link protocol providesflow control, packet framing, and error control.A Myrinet host interface, such as the Myrinet/SBus board forSPARCstations(TM), includes a processor that handles the transfer ofpacket data between the host's memory and a single Myrinet port. Theprocessor executes a control program that maps and monitors the networkcontinuously, and translates between the addresses used by the hosts(such as IP addresses) and the source routes used by Myrinet switches.A Myrinet switch is a small, low-power, self-initializing componentdesigned for operation in a wiring closet, above a ceiling, or in anyother location convenient for cabling the network. Switches with 4 or 8ports are available now; 16- and 32-port switches are in development.Myrinet exhibits a very low bit-error rate, less than one bit error perday in a large network, and is highly robust with respect to host,switch, and cable faults. Myrinet continuously maps itself and usesalternate routes, if available, to circumvent switch or cable faults.The hardware computes and checks a CRC for each packet on each link.Because Myrinet can transport packets of any length; it supports IPdirectly without an adaptation layer, and all the protocols above IP,such as TCP and FTP. Myrinet can also support other packet protocolssimultaneously on the same network. The Myrinet header identifies thepacket type (i.e., an encapsulated IP packet, a packet conveyed by alight-weight protocol, or a Myrinet mapping packet). Myrinet can carryany protocol currently supported over Ethernet. The software interfaceto Myrinet appears to higher layers just like an Ethernet interface, butwith a larger MTU.Due to its high data rate, low latency, and scalability, Myrinet isparticularly will suited for connecting computers in clusters used formultiple-computer, parallel-computing applications. No wonder; Myrinetgrew out of multicomputer technology. Myrinet is also well suited as abackbone network, and for bandwidth-intensive applications such as thetransfer of high-resolution or high-frame-rate images.

Language: C
Source Avail: No
Product Special Handling: None.
Operating Systems: Solaris Sparc 1.0,2.3,2.4,2.5

Myricom, Inc.
325 N Santa Anita Ave
Arcadia, CA 91006
USA
Phone: (818) 821-5555
Fax: (818) 821-5316

Networking Hardware

Myrinet

Myricom, Inc.