HD/FD autonegociation
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Michelot on January 31, 2008, 5:25 am
Please log in for more thread options Was it possible to achieve HD or FD selection by autonegociation, at the time where the both modes existed? Best regards, Michelot | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Walter Roberson on January 31, 2008, 10:07 am
Please log in for more thread options I am not sure what you mean by "at the time where the both modes existed" ? Half duplex came first. When full duplex was first implemented, standards in autonegotation did not exist, and it was not uncommon to see early devices that could not autonegotiate at all (but which could be configured for either half duplex or full duplex for any given port.) I would need to check historical references to find out if autonegotation was a goal in the development of full duplex or whether autonegotation was later than full duplex. | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Michelot on February 4, 2008, 11:22 am
Please log in for more thread options Bonjour Walter,
Sorry for the late, and thanks for the comments. > I am not sure what you mean by "at the time where the both modes
> existed" ? I meant the time where the collision domains were common, with hubs separated by switches and routers. > Half duplex came first. When full duplex was first implemented,
> standards in autonegotation did not exist, and it was not > uncommon to see early devices that could not autonegotiate at all > (but which could be configured for either half duplex or full > duplex for any given port.) OK, I can understand that. > I would need to check historical
> references to find out if autonegotation was a goal in the development > of full duplex or whether autonegotation was later than full duplex. Full duplex come in march 1997 with 802.3x, and autonegociation with 802.3u in june 1996. So it seems that the automatic selection of the rate was also important, and duplex selection has probably raised that fact. I read this morning, in an old book, that autonegociation was essential, necessary, with 1000Base-T. Was it correct in 2000, and is it always correct today? Thanks for the new comments, best regards, Michelot | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Walter Roberson on February 4, 2008, 1:57 pm
Please log in for more thread options
>> I would need to check historical
>> references to find out if autonegotation was a goal in the development >> of full duplex or whether autonegotation was later than full duplex. >Full duplex come in march 1997 with 802.3x, and autonegociation with
>802.3u in june 1996. So it seems that the automatic selection of the >rate was also important, and duplex selection has probably raised that >fact. That's when the standards were approved. The Synoptics 28115 and 28104 switches, and the Intel EtherExpress Pro/100 ethernet card were jointly announced May 9, 1994, with June 1994 delivery for the 28115 and August 1994 delivery for the EtherExpress. The announcement claimed that they were the world's first 100M ethernet products. ("Intel, SynOptics announce new fast Ethernet devices NetworkWorld" If you google "synoptics 28115 released" then it is the second link, but you will have to ask google for the cached version as the primary is no longer available through that link.) >I read this morning, in an old book, that autonegociation was
>essential, necessary, with 1000Base-T. Was it correct in 2000, and is >it always correct today? Yes, as far as I know; that's what the experts here keep saying. | ||||||||||||||||||||||||||||||||||||||||||||||
|
Posted by Rich Seifert on February 4, 2008, 7:56 pm
Please log in for more thread options roberson@hushmail.com (Walter Roberson) wrote:
> In article
> > The Synoptics 28115 and 28104 switches, and the > Intel EtherExpress Pro/100 ethernet card were jointly announced > May 9, 1994, with June 1994 delivery for the 28115 and August 1994 > delivery for the EtherExpress. The announcement claimed > that they were the world's first 100M ethernet products. > They can *claim* that, but the world's first 100M Ethernet products were announced and shipped in 1992 by Grand Junction Networks (later acquired by cisco). >
> >I read this morning, in an old book, that autonegociation was
> >essential, necessary, with 1000Base-T. Was it correct in 2000, and is > >it always correct today? >
> Yes, as far as I know; that's what the experts here keep saying. Yes. Auto-Negotiation is (and always has been) mandatory for 1000BASE-T. -- Rich Seifert Networks and Communications Consulting 21885 Bear Creek Way (408) 395-5700 Los Gatos, CA 95033 (408) 228-0803 FAX Send replies to: usenet at richseifert dot com | ||||||||||||||||||||||||||||||||||||||||||||||
| Similar Threads | Posted |
| HD/FD autonegociation | January 31, 2008, 5:25 am |
>the time where the both modes existed?