M2F-CB-{05 ... 35} and M2-CB-{40 ... 60}

Myrinet-LAN Cables


Myrinet-LAN Cable End

These standard Myrinet-LAN cables are 18-twisted-pair, shielded, UL type CL-2 cables terminated on both ends by industry-standard DB-37 connectors with EMI-shielding hoods, locking screws, and strain-relief fixtures. These cables are rugged, and control electromagnetic interference (EMI) to FCC A levels.

Myrinet-LAN cables in standard lengths from 5-35 feet carry packets at the 1.28+1.28 Gb/s data rate. These cables are approximately 0.34 inches in diameter, and are sufficiently flexible to bend with a 3-inch radius. In order to assure good operating margins, M2F cables are tested at a 1.6+1.6 Gb/s data rate before shipment.

Myrinet-LAN cables in standard lengths from 40-60 feet are physically identical to the 5-35 foot cables, but carry packets at the 0.64+0.64 Gb/s data rate. M2 cables are tested at a 0.96+0.96 Gb/s data rate before shipment.

It is possible for users to make their own Myrinet cables in accordance with the published specifications.

Myricom supplies optical-fiber converters for distances greater than 60 feet.



Myrinet-LAN-Cable Factoids

The DB-37 connector ports on Myrinet-LAN interfaces and switches are female. Cables have male DB-37 connectors on both ends.

Most computer cables connect a given pin on the connector on one end of the cable with the same pin on the connector on the other end. However, because Myrinet cables can be used to connect an interface to another interface, an interface to a switch, or a switch to a switch, they must provide some way of connecting a given output signal on one end to the corresponding input signal on the other end. As described in the Myrinet link and routing specifications, this input-output mapping is accomplished very simply by wiring the cables so that each pin on the connector on one end of the cable connects to the mirror-image pin on the connector on the other end. Myrinet-SAN cables employ exactly the same trick.

Users may notice that the center pin of the DB-37 connectors is missing on M2F cables. This is as it should be. M2F interfaces and switches sense whether or not this pin is connected to the shield to determine whether to operate at the 0.64+0.64 Gb/s or 1.28+1.28 Gb/s data rate.


Last significant revision: 25 February 1999 (70- & 82-foot cables discontinued)