[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference 7.286::fddi

Title:	FDDI - The Next Generation

Moderator:	NETCAD::STEFANI

Created:	Thu Apr 27 1989
Last Modified:	Thu Jun 05 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	2259
Total number of notes:	8590

1012.0. "Copper FDDI with DEC and IBM" by FRSIT::MAYER () Mon Jul 05 1993 11:02

Hi,

one of our customers tried to connect an IBM FDDI Station via TYPE1 Cable to
our DECconcentrator. Because of the incompatibility of the different
implementations this couldn't work.
As I understand there are the following implemetation variations:

o DEC -> Greene Book, "GANG OF FIVE" (DEC,AMD,CHIPCOM,MOTOROLA and SYNOPTICS)

o IBM -> has an probiarty implementation called CDDI or SDDI

So as an workaround our customer is going over to interconnect the systems by
fiber.

In the meantime our customer got the information that IBM will join the group
called "GANG OF FIVE", but DEC will leave and is going a different way.
This means no compatibility between DEC and IBM in future.

Is this correct ?
Or what is the future direction of how to run FDDI over copper ? 
Is there an future development of any common standard ?

Regards Juergen Mayer (NIS Germany/Frankfurt)

T.R	Title	User	Personal Name	Date	Lines
1012.1	there is a standard in the works	LEVERS::MELARAGNI		`Mon Jul 05 1993 20:09`	24
	As i understand it, the current versions of copper FDDI (SDDI, CDDI, gang of 5) are not supported by the ANSI standard. However, a working committee now exits to create a workable copper FDDI solution that utilizes Catagory 5 unshielded twisted pair cable. The committee is progressing nicely. So nicely, in fact, that several companies (DEC included) have taken part in a demonstration of the technology. The demo was held in Boston on June 3 and was a great technical success. The demo showed that several companies (12 or 13 at last count) could develop a workable copper-based FDDI solution from the currently existing draft standard. This is a very strong message and bodes well for the draft standard. An integral part of the new copper-based FDDI draft standard (officially called 'TP-PMD' and more informally referred to as 'UTP FDDI') is the ability to support both shielded and unshielded cables. This is vital in that if TP-PMD is ratified as a standard then a shielded twisted pair solution will also be standards-based. At this point customers can buy shielded twisted pair FDDI from any vendor and expect it to work with other vendors' equipment (assuming everyone builds standards-compliant stuff). bill melaragni UTP FDDI design team
1012.2	But maybe no one will build STP devices	JUMP4::JOY	Perception is reality	`Tue Jul 20 1993 20:17`	8
	Just one comment on the shielded version of the TP-FDDI PMD. Apparently at the interoperability demo last month, only one vendor brought STP components (and it wasn't even IBM). No one else was building any they said. So, even though a standard will exist, it wouldn't necessarily mean that products will be available on the market. Debbie
1012.3		LEVERS::MELARAGNI		`Wed Jul 21 1993 11:58`	8
	The vendor that brought the shielded UTP product to the interop demo was Technitrol. They supply various specialty-type PMD products to be used by OEMs in their FDDI stations. Several OEMs have already bought in to Technitrol, so expect to see some shielded UTP products hit the market in the future. bill
1012.4	Any DEC for Interop ?	ULYSSE::BARRIER		`Thu Jul 22 1993 09:48`	16
	Hi, I'm currently working on the FDDI SSD environment for Interop which will take place in October in Paris (France). The current network design is showing several hubs attaching PC or workstation by using SDDI type of connection. As we would like to introduice DEChub900 in this environment, does anyone know if we have a product able to support SDDI connection ? Is the DEFHU DECconcentrator 900TH can provide this functionality, and if yes can we plan to use it for Interop ? Regards. jean-claude
1012.5		KONING::KONING	Paul Koning, A-13683	`Thu Jul 22 1993 15:14`	3
	If you want interoperability, it would be best to stick to the standard. paul
1012.6	Terminology...	HERON::KNOCH	Life is Uncertain; Eat Dessert First!	`Thu Jul 22 1993 17:48`	18
	ref .1 > As i understand it, the current versions of copper FDDI (SDDI, CDDI, > gang of 5) are not supported by the ANSI standard. Could someone clear up the terminology here. I thought: - SDDI was Synchronous FDDI and can run over fiber OR copper. - CDDI was Copper FDDI (ie, FDDI protocol on copper wires) (but the acronym cannot be used because CDDI has been trademarked.) - "Gang of 5" PMD is Shielded Twisted Pair copper - TP-PMD is Unshielded Twisted Pair copper. Right??????????? Lee
1012.7		KONING::KONING	Paul Koning, A-13683	`Thu Jul 22 1993 19:34`	4
	There is no such thing as "synchronous FDDI". Synchronous transmission is a choice available to every station, on a packet by packet basis. paul
1012.8	Now I get it...	HERON::KNOCH	Life is Uncertain; Eat Dessert First!	`Fri Jul 23 1993 09:49`	9
	Ok, now I get it. SDDI is STP copper FDDI and is IBM's proprietary implementation (just as we have our own proprietery STP implementation). I had thought SDDI was Sync FDDI. At interop SF in August I believe we're showing an TP-PMD interoperability demo. I'll suggest the same for Interop Paris. Thanks! Lee
1012.9		QUIVER::STEFANI	Elvis is my psychic advisor	`Fri Jul 23 1993 11:40`	12
	>>At interop SF in August I believe we're showing an TP-PMD interoperability >>demo. I'll suggest the same for Interop Paris. I'm one of the engineers working on the UTP (TP-PMD) Interop demo being held next month. The controllers that we'll be demoing are UTP pilot versions of the DEC FDDIcontroller/EISA. I don't know when Interop Paris is, but you'll want to speak with Sharon (DELNI::ONEILL) Oneill regarding availability of the controllers. And again, if you have any configuration/driver related questions, feel free to ask. We want to see Digital's FDDI products succeed. - Larry