whlehr@leland.Stanford.EDU (William H. Lehr) (04/12/91)
Can anyone out there explain what is holding up X3T9.5's SMT standard for FDDI in (relatively) simple terms? I'm trying to understand what the different philosophies are re: what should be included vs. excluded from FDDI? Thanks in advance for help. Either post to newsgroup or respond directly via email. - Bill. WHLEHR@portia.Stanford.edu
vjs@rhyolite.wpd.sgi.com (Vernon Schryver) (04/12/91)
In article <1991Apr11.221054.25188@leland.Stanford.EDU>, whlehr@leland.Stanford.EDU (William H. Lehr) writes: > Can anyone out there explain what is holding up X3T9.5's SMT standard for > FDDI > in (relatively) simple terms? I'm trying to understand what the different > philosophies are > re: what should be included vs. excluded from FDDI? Short answer: politics Slightly longer: 1. Perhaps 20% of X3T9.5 are technical sophisticates who say "The more management, the better." They say FDDI stations cannot be expected to have enough higher layer protocol stacks to do useful network management. They are those pushing to make PMF's and so on mandatory. They are those who have said in my hearing in X3T9.5 plenary meetings "our customers do not care about security." Most in this camp are SMT software vendors, FDDI consultants, or major network users. 2. Perhaps 35% of X3T9.5 are technical sophisticates who say "Let SNMP or an OSI protocol manage things." Most system and hardware vendors are in this camp. There are some major network users in this group. This camp moans about the lack of security SMT for "sets." For example, as of San Jose, there is a broadcast frame that says "turn yourself off" or "change your address to XXX," but no authentication nor authoratization other than the single field described in the standard as "to be determined." This camp continually shouts "Enough changes and features! Finish already." 3. Perhaps 30% of X3T9.5 are by their own account less sophisticated. When they hear "more management" from the first camp, they say "of course." The result has not been pretty. About 2 years ago X3T9.5 formally agreed that everything would be "upward compatible" with the standard of the era, before there were official numbers on the versions. The first official number was about SMT 6.0. The compatible version was informally known as SMT 5.3 (or was it 5.2?). Some of the recent conflicts revolve around the desire of the first camp above to make more management frames mandatory, and the consequent conflicts with the historical compatibility agreement. The complete, private accounts of this history from any of the varied perspectives cannot, as they say, be printed in a family newspaper. Disclaimer: I work for a system vendor with a currently shipping FDDI product, and my sentiments are with the 2nd camp. This only attempts to caricature SMT; nothing is intentionally implied about FDDI-2, etc. Vernon Schryver, vjs@sgi.com
my@falcon.nsc.com (Michael Yip) (04/13/91)
In article vjs@rhyolite.wpd.sgi.com (Vernon Schryver) writes: > From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver) > Subject: Re: Info on FDDI SMT > Organization: Silicon Graphics, Inc., Mountain View, CA > > In article whlehr@leland.Stanford.EDU (William H. Lehr) writes: > > Can anyone out there explain what is holding up X3T9.5's SMT standard for > > FDDI > > in (relatively) simple terms? I'm trying to understand what the different > > philosophies are > > re: what should be included vs. excluded from FDDI? > > > Short answer: > politics 100% agree with you. But also depends on different thinking and what people expect from FDDI/SMT. Some people want more and some people want less and nothing get resolve. Also depends on technical difficulties. There are many ways to do the same thing and no one can decide what is the best way ... so we ended up doing something in the middle and things don't work ... or one or two companies pushing for their implementation only. > Slightly longer: > 1. Perhaps 20% of X3T9.5 are technical sophisticates who say "The more > management, the better." They say FDDI stations cannot be expected > to have enough higher layer protocol stacks to do useful network > management. They are those pushing to make PMF's and so on > mandatory. They are those who have said in my hearing in X3T9.5 > plenary meetings "our customers do not care about security." Most > in this camp are SMT software vendors, FDDI consultants, or major > network users. It is hard to say that they are wrong. More is better, right? Well, PMF is not bad but do we really need all the extra? ... we don't know and that's why it's taking so long to agree upon. > 2. Perhaps 35% of X3T9.5 are technical sophisticates who say "Let > SNMP or an OSI protocol manage things." Most system and hardware > vendors are in this camp. There are some major network users in > this group. This camp moans about the lack of security SMT for > "sets." For example, as of San Jose, there is a broadcast frame > that says "turn yourself off" or "change your address to XXX," but > no authentication nor authoratization other than the single field > described in the standard as "to be determined." This camp > continually shouts "Enough changes and features! Finish already." I am in the camp of saying "let SNMP or OSI manage things" ... but I don't shout "Enough changes and Done." I think that we should have a minimum set of functions and extra (eg PMFs) should be just extra. That way people can get on implementing FDDI now and add extra later without breaking things. For example, one don't have to support PMF change until the AUTH field is clearly defined. The earlier that we get SMT and FDDI out the door, the more popular FDDI will be ... or else we will miss the market window and FDDI will be yet another vapor_net. > 3. Perhaps 30% of X3T9.5 are by their own account less sophisticated. > When they hear "more management" from the first camp, they say "of > course." > [....] > Vernon Schryver, vjs@sgi.com Well, this is my own opinion so don't flame me for that. ;) -- Mike Yip my@berlioz.nsc.com PS: BY the way, what do people think about FDDI-2??
vjs@rhyolite.wpd.sgi.com (Vernon Schryver) (04/14/91)
In article <1991Apr12.233143.722@berlioz.nsc.com>, my@falcon.nsc.com (Michael Yip) writes: > ... > I am in the camp of saying "let SNMP or OSI manage things" ... but I don't > shout "Enough changes and Done." I think that we should have a minimum > set of functions and extra (eg PMFs) should be just extra. That way > people can get on implementing FDDI now and add extra later without breaking > things. .... > The earlier that we get SMT and FDDI out the > door, the more popular FDDI will be ... or else we will miss the market > window and FDDI will be yet another vapor_net. > -- Mike Yip > my@berlioz.nsc.com > PS: BY the way, what do people think about FDDI-2?? I've been muttering for many years on a many subjects "any fool can add features; the trick is in leaving them out." PMF's etc would have been a keen idea 5 years ago, before SNMP, before the market decide INTERnetwork management was possible and desirable. At this late date, it is strange to delay SMT to perfect a network management scheme that only works on the local ring not even crossing bridges, to believe that TCP is hard in these days of free 4.3BSD and KA9Q source and dirt cheap MB RAMs and Mbit PROMS, to mandate a link layer management that needs a transport with most of the machinery of UDP/IP (the worst case size of some of the frames is >4500bytes). It's as if some in X3T9.5 have commercial death wishes. Instead of delaying to elaborate and fix PMF's, X3T9.5 should have finished SMT 3 years ago, and started a SMT2 with all of the bells and whistles. In the interum we could have seen how NIF's etc. really work, to find what fails in real life. (I type this after having to come in Sat. night to clean up after a power failure in a multi-building ring used by primary source machines--two few optical bypasses can give you sausage--big surprise.) The good news is that many customers and vendors are going ahead, treating the current standard like the Ethernet Blue book of old, and building, shipping, buying, and installing networks. How are people planning to use FDDI2? (That's an honest question; I wasn't paying attention when it started.) FDDI is theoretically 10x ethernet. Any pair of cheap 1990 workstations worth buying can staturate one ethernet (i.e. get around 1MByte/sec with ttcp). How are you going to have any useful bandwidth left in FDDI2 if you reserve enough to do video? Doesn't one video channel need >= 5MByte/sec? Vernon Schryver, vjs@sgi.com
my@falcon.nsc.com (Michael Yip) (04/15/91)
> PMF's etc would have been a keen idea 5 years ago, before SNMP, before the > market decide INTERnetwork management was possible and desirable. At this > late date, it is strange to delay SMT to perfect a network management > scheme that only works on the local ring not even crossing bridges, to > believe that TCP is hard in these days of free 4.3BSD and KA9Q source and > dirt cheap MB RAMs and Mbit PROMS, to mandate a link layer management that > needs a transport with most of the machinery of UDP/IP (the worst case size > of some of the frames is >4500bytes). It's as if some in X3T9.5 have > commercial death wishes. Well some people believe in FDDI-2 and hope that FDDI-1 takes off later so that FDDI-2 will be in better shape. Some people also sell SMT software, the harder and more complicate SMT gets to be ... the more copies that they can sell. I agree that UDP/IP is easy to get and we should just leave those functions to SNMP by expanding SNMP MIB. > Instead of delaying to elaborate and fix PMF's, X3T9.5 should have finished > SMT 3 years ago, and started a SMT2 with all of the bells and whistles. > In the interum we could have seen how NIF's etc. really work, to find what > fails in real life. Well, just remember that it took a LONG time to define the NIF also ... it was defined once and then state machines were added so that people can understand how to implement NIF ... it's sad. In general, I agree with you and we should have a "SMT1" which is a stripped down version of SMT. > The good news is that many customers and vendors are going ahead, treating > the current standard like the Ethernet Blue book of old, and building, > shipping, buying, and installing networks. I sure hope that people go ahead with FDDI-1 and SMT (draft) ... otherwise no one will buy FDDI chips from my company and my job will be gone. ;) > > How are people planning to use FDDI2? (That's an honest question; I wasn't > paying attention when it started.) > FDDI is theoretically 10x ethernet. Any pair of cheap 1990 workstations > worth buying can staturate one ethernet (i.e. get around 1MByte/sec with > ttcp). How are you going to have any useful bandwidth left in FDDI2 if you > reserve enough to do video? Doesn't one video channel need >= 5MByte/sec? Don't know what good FDDI-2 can do with video/multimedia ... it is just to slow for things like that. And if FDDI-2/SMT-2 take another 2 years to finalize then we might as well forget about FDDI-2 because applications demand a LOT more than 100Mbit/s then. > Vernon Schryver, vjs@sgi.com -- Mike Yip my@berlioz.nsc.com