Per ANSI/IEEE 8032.3x Ethernet Cat 5, 6, and 7 cables have only two ports, additional ports are forbidden. Both ports are transformer isolated for a 100-ohm impedance termination. Communication to other network locations is always through an active device (e.g. hub, switch, router).
The only variation is full-duplex communication where 4 lines are active and connexion is to a switch (hubs do not support full duplex). In full-duplex both ports have two transformer terminations, one for transmit and the other for receive. Ethernet adapter cards (NICS) support full duplex, but negotiate to half duplex if connected to a hub. . Honeywell David W. Sterner Quality Assurance Engineering Security & Custom Electronics 165 Eileen Way P.O. Box 9035 Syosset, NY 11791 Phone: (516) 921-6704 x6970 Fax # (516) 364-6953 david.ster...@honeywell.com <http://www.honeywell.com> david.ster...@ieee.org <http://www.IEEE.LI> Electromagnetic Compatibility IEEE 05888136 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc