On 10/10/2013 01:16 PM, Hans Vlems wrote:
Fddi was the answer for production plants that required 100% uptime
Only once did Fddi let me down and made me go back to work at 3:30 am,
the worst time to wake up. One of the boards in a gs/fddi failed,
isolating two plants.
I did manage to explode a power supply in a gs. Made one hell of bang,
fortunately that part was redundant so the net stayed up.
Yuck!
Compared to fast ethernet, I prefer fddi.
Same here.
Too expensive for private or hobbyist use though.
Hardly. You just need the right connections. I was nearly 100% FDDI
on my home network in the mid-1990s...didn't take all that much money.
I didn't have much! ;)
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
On 10 Oct 2013, at 19:12, Brian Hechinger <wonko at 4amlunch.net> wrote:
On Thu, Oct 10, 2013 at 06:33:15PM +0200, Sampsa Laine wrote:
Sounds like a business opportunity, basically build an enclosure, get 5-6 consumer SSDs, RAID6 them, expose a SCSI/SAS/eSATA interface to the host. If one of the drives breaks/runs out of write cycles, the box indicates the slot and we provide a new SSD for the slot.
FreeBSD can do this easily enough.
In most cases (like my 4000/90, for example) that's way overkill. I just
want to be able to plug something in that would replace the internal
disks.
If I were doing this. I still think my 4000/90 is going to get hooked
up to a little MSA of some sort.
I was more thinking about selling this to "enterprise" users, not hobbyists :)
The device would be packaged as a black box with no configuration etc needed - it just looks like a SCSI drive to the bus.
It could provide more space, redundancy and speed for lower cost if built right..
Sampsa
No it is one frame, cannot be split. There is a half sized gs but it has its boards mounted horizontally
Van: Brian Hechinger
Verzonden: donderdag 10 oktober 2013 17:25
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Thu, Oct 10, 2013 at 03:19:53PM +0000, Paul_Koning at Dell.com wrote:
>
>> I think this is the one I had. Big modular thing. Maybe (and going by
>> really fuzzy memory here) 8U high?
>
> I was going to say "that sounds right" based on my memory of seeing one gathering dust around here. But the picture here: http://www.global-itcorp.com/products/digital-dec/networking/gigaswitch/ shows a much taller enclosure, half line card space and half power supply. Each section does look like 8U or so.
Hmmm. I wonder if those can be separated. I wonder if that also means
mine never would have worked. I don't remember having the bottom half.
That was also 10 years ago, so who knows, maybe I did have the whole
thing. :)
> Some searching turns up refurbished Gigaswitch modules. Some are pretty cheap, but it looks like those are ATM ones, the FDDI ones I see quoted are more expensive. Perhaps because FDDI was fairly successful at least for a short time, while ATM (as a LAN) was an utter failure.
The *only* thing I even needed it to do was bridge FDDI/FastEthernet so
it just ended up not being worth the effort.
It's not a small switch. :)
-brian
On Thu, Oct 10, 2013 at 01:13:26PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 01:05 PM, Brian Hechinger wrote:
On Thu, Oct 10, 2013 at 01:01:06PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Brian Hechinger wrote:
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
If that stuff is indeed still in that barn, you can have most of it. :)
If memory serves, a good bit of that is mine. ;)
-Dave
I'll take what isn't yours. ;)
Nah, you can have Dave's stuff too. :)
-brian
Fddi was the answer for production plants that required 100% uptime
Only once did Fddi let me down and made me go back to work at 3:30 am, the worst time to wake up. One of the boards in a gs/fddi failed, isolating two plants.
I did manage to explode a power supply in a gs. Made one hell of bang, fortunately that part was redundant so the net stayed up. Compared to fast ethernet, I prefer fddi. Too expensive for private or hobbyist use though.
Van: Paul_Koning at Dell.com
Verzonden: donderdag 10 oktober 2013 17:20
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Oct 10, 2013, at 10:35 AM, Brian Hechinger <wonko at 4amlunch.net<mailto:wonko at 4amlunch.net>> wrote:
On Thu, Oct 10, 2013 at 02:32:26PM +0000, Paul_Koning at Dell.com<mailto:Paul_Koning at Dell.com> wrote:
...
Then there is the Gigaswitch, a large modular chassis with lots of line cards, some FDDI, some Ethernet, possibly some with other stuff I don't remember.
I think this is the one I had. Big modular thing. Maybe (and going by
really fuzzy memory here) 8U high?
I was going to say "that sounds right" based on my memory of seeing one gathering dust around here. But the picture here: http://www.global-itcorp.com/products/digital-dec/networking/gigaswitch/ shows a much taller enclosure, half line card space and half power supply. Each section does look like 8U or so.
Some searching turns up refurbished Gigaswitch modules. Some are pretty cheap, but it looks like those are ATM ones, the FDDI ones I see quoted are more expensive. Perhaps because FDDI was fairly successful at least for a short time, while ATM (as a LAN) was an utter failure.
paul
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 12:57 PM, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 03:04 PM, Peter Lothberg wrote:
FDDI/CDDI is a dual ring token ring bus, with 4470 MTU byte packets,
it has 802.-- frames. DEC had a mode where you turned the token off
and used it for ptp full duplex.
I didn't know about the ptp thing. That's nifty.
A cisco FDDI-PA can talk both in a 7500 or old 7200 (the VXR don't
support the FDDI cards but the VIP does ).
About that, Peter...is there ANY way to get a FDDI PAM to run in a
7206VXR? Or will it just plain not work, ever?
I thought PAs were compatible across all chassis? Maybe in a VXR with
an STD NPE?
No, not all PAs are supported in all chassis. I think that was
Cisco's way of forcing premature obsolecense on some things.
You know what I think about that. ;)
Time to throw out Cisco specs and make it work anyway!
I need EEPROM debugging tools.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
Hello!
I was always told that a 1RU shape was about the size of a pizza box.
Since pizza and I are not on speaking terms I simply took the
individual's words for factual information until told otherwise.
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."
On Thu, Oct 10, 2013 at 1:12 PM, Cory Smelosky <b4 at gewt.net> wrote:
On Thu, 10 Oct 2013, Hans Vlems wrote:
A hu is two inches, right?
It's actually some uneven number that's around 1.5.
Van: Brian Hechinger
Verzonden: donderdag 10 oktober 2013 16:35
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Thu, Oct 10, 2013 at 02:32:26PM +0000, Paul_Koning at Dell.com wrote:
On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net>
wrote:
On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
...
For example cisco/cabletron/crecendo had ethnernet switches with a
FDDI uplink, that you could use.
DEC made one as well, it was that large modular thingie. I used to
have
one. Never got it powered on as it was enormous.
The original one is the DECbridge 500, a 3U rack mounted device, 3 or 4
cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ
issue I mentioned in my previous note.
The other two: the DECbridge 900, which plugged into the 900 series
modular enclosure. It's about the side of a 400 page
hardcover book, FDDI to 6 Ethernet ports, 60,000 packets per second using
a MC68040 at 25 MHz. I'm still proud of that. (I wrote
the "fast path" packet forwarding firmware.)
Neat!
Then there is the Gigaswitch, a large modular chassis with lots of line
cards, some FDDI, some Ethernet, possibly some with
other stuff I don't remember.
I think this is the one I had. Big modular thing. Maybe (and going by
really fuzzy memory here) 8U high?
-brian
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On 10/10/2013 01:12 PM, Cory Smelosky wrote:
A hu is two inches, right?
It's actually some uneven number that's around 1.5.
1.75".
--
Dave McGuire, AK4HZ
New Kensington, PA
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 01:05 PM, Brian Hechinger wrote:
On Thu, Oct 10, 2013 at 01:01:06PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Brian Hechinger wrote:
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
If that stuff is indeed still in that barn, you can have most of it. :)
If memory serves, a good bit of that is mine. ;)
-Dave
I'll take what isn't yours. ;)
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On Thu, Oct 10, 2013 at 06:33:15PM +0200, Sampsa Laine wrote:
Sounds like a business opportunity, basically build an enclosure, get 5-6 consumer SSDs, RAID6 them, expose a SCSI/SAS/eSATA interface to the host. If one of the drives breaks/runs out of write cycles, the box indicates the slot and we provide a new SSD for the slot.
FreeBSD can do this easily enough.
In most cases (like my 4000/90, for example) that's way overkill. I just
want to be able to plug something in that would replace the internal
disks.
If I were doing this. I still think my 4000/90 is going to get hooked
up to a little MSA of some sort.
-brian
On Thu, 10 Oct 2013, Hans Vlems wrote:
A hu is two inches, right?
It's actually some uneven number that's around 1.5.
Van: Brian Hechinger
Verzonden: donderdag 10 oktober 2013 16:35
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Thu, Oct 10, 2013 at 02:32:26PM +0000, Paul_Koning at Dell.com wrote:
> >
> > On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
> >
> >> On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
> >>> ...
> >>> For example cisco/cabletron/crecendo had ethnernet switches with a
> >>> FDDI uplink, that you could use.
> >>
> >> DEC made one as well, it was that large modular thingie. I used to have
> >> one. Never got it powered on as it was enormous.
>
> The original one is the DECbridge 500, a 3U rack mounted device, 3 or 4 cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ
issue I mentioned in my previous note.
>
> The other two: the DECbridge 900, which plugged into the 900 series modular enclosure. It's about the side of a 400 page
hardcover book, FDDI to 6 Ethernet ports, 60,000 packets per second using a MC68040 at 25 MHz. I'm still proud of that. (I wrote
the "fast path" packet forwarding firmware.)
Neat!
> Then there is the Gigaswitch, a large modular chassis with lots of line cards, some FDDI, some Ethernet, possibly some with
other stuff I don't remember.
I think this is the one I had. Big modular thing. Maybe (and going by
really fuzzy memory here) 8U high?
-brian
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
If you mean a RU, Rack Unit...that's 1.75".
-Dave
On 10/10/2013 01:08 PM, Hans Vlems wrote:
A hu is two inches, right?
*Van: *Brian Hechinger
*Verzonden: *donderdag 10 oktober 2013 16:35
*Aan: *hecnet at Update.UU.SE
*Beantwoorden: *hecnet at Update.UU.SE
*Onderwerp: *Re: [HECnet] FDDI advice
On Thu, Oct 10, 2013 at 02:32:26PM +0000, Paul_Koning at Dell.com wrote:
On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
...
For example cisco/cabletron/crecendo had ethnernet switches with a
FDDI uplink, that you could use.
DEC made one as well, it was that large modular thingie. I used to have
one. Never got it powered on as it was enormous.
The original one is the DECbridge 500, a 3U rack mounted device, 3 or
4 cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ issue I mentioned in
my previous note.
The other two: the DECbridge 900, which plugged into the 900 series
modular enclosure. It's about the side of a 400 page hardcover book,
FDDI to 6 Ethernet ports, 60,000 packets per second using a MC68040 at
25 MHz. I'm still proud of that. (I wrote the "fast path" packet
forwarding firmware.)
Neat!
Then there is the Gigaswitch, a large modular chassis with lots of
line cards, some FDDI, some Ethernet, possibly some with other stuff I
don't remember.
I think this is the one I had. Big modular thing. Maybe (and going by
really fuzzy memory here) 8U high?
-brian
--
Dave McGuire, AK4HZ
New Kensington, PA
On 10/10/2013 12:57 PM, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 03:04 PM, Peter Lothberg wrote:
FDDI/CDDI is a dual ring token ring bus, with 4470 MTU byte packets,
it has 802.-- frames. DEC had a mode where you turned the token off
and used it for ptp full duplex.
I didn't know about the ptp thing. That's nifty.
A cisco FDDI-PA can talk both in a 7500 or old 7200 (the VXR don't
support the FDDI cards but the VIP does ).
About that, Peter...is there ANY way to get a FDDI PAM to run in a
7206VXR? Or will it just plain not work, ever?
I thought PAs were compatible across all chassis? Maybe in a VXR with
an STD NPE?
No, not all PAs are supported in all chassis. I think that was
Cisco's way of forcing premature obsolecense on some things.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
On 10/10/2013 12:55 PM, Brian Hechinger wrote:
All this talk of FDDI makes me want to go get the 4000/500s. I have a
pair of QBus FDDI cards. I suppose I would have to make the Octane a
router between FDDI and ethernet. :)
Are any of those 4000/500s mine? ;)
Nope. I picked these up from Villanova University several years ago.
I was interviewing at a place recently and the subject of VAXen came up.
Interviewer: "I remember have an account on a pair of 4000/500s in a
cluster when I was at Villanova years ago."
Me: "Those machines are at my house now!"
Interviewer: "NO WAY!"
That's cool. :-)
I had quite a few machines up
here in your old place at one point. Don't worry, I'd only be after one
of them, and even that is low-priority at this point.
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Well, let me know when you're able to. Even if you can't move it all
down there, if you can just come up by car, you and I can head over
there with a truck, and the stuff (even yours) can sit here for awhile.
At least then it won't be in a barn, and won't be at risk in any way.
We could probably do it over a weekend trip, even on a liesurely schedule.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
The 900 series didn't support cddi iitc
Van: Mark Wickens
Verzonden: donderdag 10 oktober 2013 16:59
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On 10/10/2013 15:32, Paul_Koning at Dell.com wrote:
>> On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
>>
>>> On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
>>>> ...
>>>> For example cisco/cabletron/crecendo had ethnernet switches with a
>>>> FDDI uplink, that you could use.
>>> DEC made one as well, it was that large modular thingie. I used to have
>>> one. Never got it powered on as it was enormous.
> DEC made at least three.
>
> The original one is the DECbridge 500, a 3U rack mounted device, 3 or 4 cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ issue I mentioned in my previous note.
>
> The other two: the DECbridge 900, which plugged into the 900 series modular enclosure. It's about the side of a 400 page hardcover book, FDDI to 6 Ethernet ports, 60,000 packets per second using a MC68040 at 25 MHz. I'm still proud of that. (I wrote the "fast path" packet forwarding firmware.)
>
> Then there is the Gigaswitch, a large modular chassis with lots of line cards, some FDDI, some Ethernet, possibly some with other stuff I don't remember.
>
> paul
I meant to say that I have a DEC VNswitch 900XX plugged into a DEChub
One MX - there are clearly modular parts to that, but I'm presuming
there isn't a FDDI copper module that I would be able to use?
Thanks, Mark.
--
http://www.wickensonline.co.ukhttp://hecnet.euhttp://declegacy.org.ukhttp://retrochallenge.nethttps://twitter.com/#!/%40urbancamo
On Oct 10, 2013, at 12:39 PM, Hans Vlems <hvlems at zonnet.nl> wrote:
Bridges create an extended LAN and DECnet areas may use the entire LAN, all segments that are not behind a DECnet router.
The LAN doesn't have to be just ethernet. As long as bridges are used to connect ethernet to FDDI, or ATM or token ring then DECnet areas can easily be used across that network.
Mostly yes. When mixing LAN types, the differences in max packet size can make trouble. The simplest answer is to use the Ethernet limit.
Also, token ring is not compatible with real LANs because it doesn't use real multicast. (Well, it could in theory, but IBM insisted on being incompatible.) There's a DECnet variant that copes with this, but regular Phase IV will not work over token ring. Any real LAN, including oddballs like token bus (802.4) will be fine.
paul
On 10/10/2013 01:05 PM, Brian Hechinger wrote:
On Thu, Oct 10, 2013 at 01:01:06PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Brian Hechinger wrote:
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
If that stuff is indeed still in that barn, you can have most of it. :)
If memory serves, a good bit of that is mine. ;)
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
On Thu, 10 Oct 2013, Brian Hechinger wrote:
On Thu, Oct 10, 2013 at 01:01:06PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Brian Hechinger wrote:
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
If that stuff is indeed still in that barn, you can have most of it. :)
How much would fit in my house then becomes the question. ;)
-brian
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
A hu is two inches, right?
Van: Brian Hechinger
Verzonden: donderdag 10 oktober 2013 16:35
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Thu, Oct 10, 2013 at 02:32:26PM +0000, Paul_Koning at Dell.com wrote:
> >
> > On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
> >
> >> On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
> >>> ...
> >>> For example cisco/cabletron/crecendo had ethnernet switches with a
> >>> FDDI uplink, that you could use.
> >>
> >> DEC made one as well, it was that large modular thingie. I used to have
> >> one. Never got it powered on as it was enormous.
>
> The original one is the DECbridge 500, a 3U rack mounted device, 3 or 4 cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ issue I mentioned in my previous note.
>
> The other two: the DECbridge 900, which plugged into the 900 series modular enclosure. It's about the side of a 400 page hardcover book, FDDI to 6 Ethernet ports, 60,000 packets per second using a MC68040 at 25 MHz. I'm still proud of that. (I wrote the "fast path" packet forwarding firmware.)
Neat!
> Then there is the Gigaswitch, a large modular chassis with lots of line cards, some FDDI, some Ethernet, possibly some with other stuff I don't remember.
I think this is the one I had. Big modular thing. Maybe (and going by
really fuzzy memory here) 8U high?
-brian
There was a gs/atm and a gs/fddi. I cannot remember fast ethernet for the gs/fddi.
Mainly because we used Dec hub 900 modules to step down to regular ethernet, fast ethernet only for alphas.
Van: Paul_Koning at Dell.com
Verzonden: donderdag 10 oktober 2013 16:32
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
>
> On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
>
>> On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
>>> ...
>>> For example cisco/cabletron/crecendo had ethnernet switches with a
>>> FDDI uplink, that you could use.
>>
>> DEC made one as well, it was that large modular thingie. I used to have
>> one. Never got it powered on as it was enormous.
DEC made at least three.
The original one is the DECbridge 500, a 3U rack mounted device, 3 or 4 cards, 3 Ethernets (10 Mb/s) to FDDI. See the DTJ issue I mentioned in my previous note.
The other two: the DECbridge 900, which plugged into the 900 series modular enclosure. It's about the side of a 400 page hardcover book, FDDI to 6 Ethernet ports, 60,000 packets per second using a MC68040 at 25 MHz. I'm still proud of that. (I wrote the "fast path" packet forwarding firmware.)
Then there is the Gigaswitch, a large modular chassis with lots of line cards, some FDDI, some Ethernet, possibly some with other stuff I don't remember.
paul
On Thu, Oct 10, 2013 at 01:01:06PM -0400, Cory Smelosky wrote:
On Thu, 10 Oct 2013, Brian Hechinger wrote:
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
If that stuff is indeed still in that barn, you can have most of it. :)
-brian
Paul, at Fuji we used the Dec bridge 500 and 600 series, the decconcentrator 550 and the gigaswitch/fddi. It worked ver reliable to the point that I had serious problems obtaining budget to put some redundancy in the LAN. Three rings needed at least 4 gigaswitches.
Hans
Van: Paul_Koning at Dell.com
Verzonden: donderdag 10 oktober 2013 16:26
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
On Oct 10, 2013, at 8:44 AM, Brian Hechinger <wonko at 4amlunch.net> wrote:
> On Thu, Oct 10, 2013 at 02:36:04PM +0200, Peter Lothberg wrote:
>>
>> FDDI/CDDI is a dual ring token ring bus, with 4470 MTU byte packets,
>> it has 802.-- frames. DEC had a mode where you turned the token off
>> and used it for ptp full duplex.
>
> I didn't know about the ptp thing. That's nifty.
>
>> For example cisco/cabletron/crecendo had ethnernet switches with a
>> FDDI uplink, that you could use.
>
> DEC made one as well, it was that large modular thingie. I used to have
> one. Never got it powered on as it was enormous.
>
>> But you need nothing to build a FDDI ring, its a A and a B ring, you
>> can just plug the cards together with fiber-patch-cables.
>
> Unless you have one of those obnoxious single attached station cards.
>
> -brian
Ah, time to dust off some dormant memories. I used to work on the FDDI standard at DEC; this stuff is familiar.
"CDDI" is marketing slang; it is not standard terminology.
FDDI is different from Ethernet; the MAC layer protocol is completely unrelated. It's quite similar to token bus (802.4), actually. (The only thing it has in commoni with 802.5 is the words "token" and "ring" -- apart from that, the two protocols operate completely differently.)
FDDI connections have a "type", which can be "A", "B", "S", or "M". "M" ports exist on concentrators. NICs will have A and B ports, if there are two connectors on the NIC ("dual attached station" or DAS) or an S port, if there is one connector (single attached station or SAS).
You have a number of topology options.
If you have DAS NICs, you can wire any number of them together in a "dual ring". That's the original FDDI topology, before DEC forced concentrators to be added into the standard. To do that, connect the NICs in circular fashion, A to B. Connected that way, loss of any single connection is handled transparently.
If you have SAS NICs. you can connect a pair of them (S to S).
If you have DAS NICs plus or or two SAS, wire the DAS NICs A-B in a chain (essentially a dual ring cut open). Then connect a SAS to each end (or just to one end, if you have one SAS). There is no redundancy in this config.
Finally, if you have any concentrators, you can build a tree config out of those. If so, the M connectors connect to the NIC connectors (A, B, or S), and the concentrator's A and B connectors either connect to M ports higher up in the hierarchy, or in a dual ring if you have a ring of concentrators, or nowhere if you're at the root of a tree.
FDDI fiber connectors are standardized but different from fiber connectors used by other networks. The connector is fairly large, flat rectangular with a shroud covering the fiber ends. Connectors are keyed to match the port type, though you can omit the keys and just wire carefully. Standard fiber is 62.5/125 micrometer, but 50/125 also works.
You can find more in the DEC Technical Journal, Vol. 3 No. 2, spring 1991. Or the relevant ANSI/ISO standards if you are a masochist. The topology rules are described fairly well in the concentrator article in DTJ, but their full glory can be found in the FDDI "SMT" (station management" standard.
paul
On Thu, 10 Oct 2013, Brian Hechinger wrote:
On Thu, Oct 10, 2013 at 12:36:47PM -0400, Dave McGuire wrote:
On 10/10/2013 10:29 AM, Brian Hechinger wrote:
All this talk of FDDI makes me want to go get the 4000/500s. I have a
pair of QBus FDDI cards. I suppose I would have to make the Octane a
router between FDDI and ethernet. :)
Are any of those 4000/500s mine? ;)
Nope. I picked these up from Villanova University several years ago.
I was interviewing at a place recently and the subject of VAXen came up.
Interviewer: "I remember have an account on a pair of 4000/500s in a
cluster when I was at Villanova years ago."
Me: "Those machines are at my house now!"
Interviewer: "NO WAY!"
I had quite a few machines up
here in your old place at one point. Don't worry, I'd only be after one
of them, and even that is low-priority at this point.
Going and rescuing all that stuff is something I really want to do one
day. Not anytime soon though. :(
Save me one! ;)
-brian
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On Thu, 10 Oct 2013, Dave McGuire wrote:
On 10/10/2013 11:59 AM, Mark Wickens wrote:
... I have a DEC VNswitch 900XX plugged into a DEChub One MX - there
are clearly modular parts to that, but I'm presuming there isn't a
FDDI copper module that I would be able to use?
That looks different (same size, though). The one I was talking about
is the DECbridge 900. I see some variations on the net -- DECbridge
900MX seems to be the same except that it has two AUI connectors
instead of being all 10Base-T. And I think the original was a SAS (S
port) while the MX is a DAS (A and B ports).
http://decdoc.itsx.net/dec94mds/defbaina.pdf has details and a picture.
paul
Unfortunately, as nice a box as it is (that counts for most things with
a 68k in ;) FDDI to 10MB doesn't solve any problems for me as the sole
benefit is the jump to 100MB over the standard ethernet card in the
3000/800, so any solution that is going to work would need to give me
access to 100MB+ at the other end of the FDDI.
The best way I've found to do this is to do it at the switch level.
(I have run lots and lots of FDDI, at work and home)
What I'd recommend is to pick up a Cisco Catalyst 5000 or 5500. That
can take lots of Ethernet modules, covering 10/100/1000Mbps, and there
are FDDI modules for them as well.
Or a Catalyst 4000! I was offered 36 of them...I'd not quite have room for 36 10U switches in my home...
These are very fast, very reliable switches.
You can also get an RSM, the Route-Switch Module, which is basically a
7500 router on a board. It routes between VLANs on the switch, and in
that capacity can do most anything a full standalone 7500-class router
can do. It's got a separate console interface, separate PCMCIA slots,
etc...it's like a standalone router.
Can it take its own modules though?
Perhaps I should upgrade from a 3745 at the core of my house...;)
The Catalys 5x00 switches do full translational bridging for FDDI. I
haven't found any networking scenario that doesn't work when mixing and
matching and translating between different networking media in one of
those switches.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On Thu, Oct 10, 2013 at 12:38:19PM -0400, Dave McGuire wrote:
On 10/10/2013 10:35 AM, Brian Hechinger wrote:
The other two: the DECbridge 900, which plugged into the 900 series
modular enclosure. It's about the side of a 400 page hardcover
book, FDDI to 6 Ethernet ports, 60,000 packets per second using a
MC68040 at 25 MHz. I'm still proud of that. (I wrote the "fast
path" packet forwarding firmware.)
Neat!
That's not "neat"...that's AWESOME. Just pointing it out..
Ok, yes. :)
Then there is the Gigaswitch, a large modular chassis with lots of
line cards, some FDDI, some Ethernet, possibly some with other
stuff I don't remember.
I think this is the one I had. Big modular thing. Maybe (and going
by really fuzzy memory here) 8U high?
A GigaSwitch is a lot more than 8U high. Try nearly half a rack.
Yeah, I'm starting to believe I only had half of one. Good thing I never
tried to use it. :)
-brian
