Agreed. I think my brain was on vacation when I read your original post;
sorry for any confusion. Chalk it up to a very long day. :-)
Anyway, I did some large scale video-conference setups a number of years
ago and my only choice for reliability, CODEC to CODEC, was ATM. We had
excellent results with a multipoint Voice, Video, Data mux.
Craig
At 10:26 PM 10/12/2000 -0400, you wrote:
>You are not really going to get the full benefits of going ATM to the
>desktop until the Apps running on the client are ATM aware.
>
>Running LANE or doing 1483 is still not going to give you a good COS as you
>would be using AAL5 anyway, which is UBR.
>
>Some VTC ( Video Teleconferencing ) vendors are doing ATM, such as
>http://www.vtel.com but are using native ATM to simulate B-ISDN over ATM
>and breaking it out before it hits the PC bus, into a CODEC.
>
>ATM is really good on the backbone though and you can have different PVC's
>going into the same router and make different paths. IE: one path/PVC/SVC
>for regular bursty data, another for multicast, another for VTC, another for
>H.323 voice/video, etc.
>
>Scott
>
>
>
> > Not to shift the subject, but if you need the consistent latency and
> > reliability for multimedia, why not go with ATM? The bandwidth available
> > is better than Token ring and the cost isn't *that* much more.
> > In any case, SNA over Ethernet is no problem in a well-designed
> > network. As Priscilla stated, IBM has the market for most of the high-end
> > hardware that utilizes SNA, IBM likes(d) token ring, and change is a hard
> > thing to come by in the world of Big Blue.
> >
> > Just my $0.02...
> > Craig
> >
> > At 04:20 PM 10/12/2000 -0400, you wrote:
> >> > At 08:19 AM 10/12/00, Alldread AK2 Robert J wrote:
> >> >>I am just curious as to why SNA still runs on tokenring today.
> >> >
> >> > IBM got their foot in the door at many large companies and then
> closed the
> >> > door behind them. The end result is that many companies deployed all
> >> > IBM-developed technologies. If a company uses their network for
> >> > mission-critical applications, it takes a long time for the network to
> >> > evolve, since changes risk bringing the network down.
> >>
> >>It's actually more than that though. Token Ring and FDDI are token passing
> >>in nature and can have predictable response times. Ethernet is bursty by
> >>nature and, although good for most everybody needs, still has issues in the
> >>QoS or what I call Best Effort QoS, for what Token Ring already offers,
> >>which is consistent, predictable network response times.
> >>With SNA, that is very important.
> >>
> >>I have seen companies go through a lot of planning into putting Video
> >>Conferencing using H.323 over IP and it's still a headache. Where in the
> >>Token Ring world of 100Mb Token Ring ( yes it exists ), this is a lot
> easier
> >>as it already offers QoS-ing ( made that word up <g> ) and has done so for
> >>years.
> >>
> >> >> Is there any
> >> >>reason that it cannot just hook right into an ethernet network??
> >>
> >>-->You can use Ethernet and although, a little harder to setup, but
> works OK
> >>provided you don't have an over saturated network and your support staff
> >>knows how it works. It still rears up every now and then.
> >>
> >> > SNA can run on Ethernet. IBM and other vendors support this. It's
> actually
> >> > somewhat common.
> >> >
> >> >> I have
> >> >>read a few white papers on SNA, and I assume that because tokenring
> was the
> >> >>major LAN media back in the day, and because SNA uses RIF's to determine
> >> >>paths to other hosts, that SNA was built requiring the use of RIF's. Is
> >> >>this correct??
> >> > Historically this is not correct. SNA has its own complex path
> >> > determination methods that were used on large "internetworks" long
> before
> >> > Token Ring and source-route bridging were ever invented. Long before
> LANs
> >> > were invented, come to think of it. SNA shipped in 1974, (though it
> didn't
> >> > catch on right away.) Token Ring's birth date is more like 1984.
> >> >
> >> > The Internetworking Technologies Handbook does a pretty good job
> with SNA.
> >> > SNA is surprisingly still common, as is Token Ring. (At least in
> Southern
> >> > Oregon where I live!? &;-)
> >>
> >>-->I do a lot of work for a Movie production company that uses Token Ring
> >>because of all of the Multimedia they do. We tried a lot of different
> >>Ethernet solutions but just couldn't get it to perform well.
> >>For most people, Ethernet works fine as most of the usual traffic is
> E-Mail,
> >>Web, file and print, which aren't latency sensitive.
> >>
> >>However, to multimedia rendering, video conferencing, Voice, SNA, etc, that
> >>are very latency sensitive, it makes a big difference.
> >>
> >>Sorry for the Token Ring speech. <g> and no, I don't sell it.
> >>
> >>Madge has a pretty decent paper on it:
> >>
> >>http://www.madge.com/Connect/Downloads/Documents/content.asp?Article=536
> &Sub
> >>Area=
> >>
> >>IMHO, it is a lot better than Ethernet but the price killed it.
> >>Sometimes, you do get what you paid for though.... ;-)
> >>
> >>It's funny, I have seen companies put a lot of money into QoS strategies,
> >>that, had they just done Token Ring in the first place, would have cost
> them
> >>less and had less support issues in the long run. <g>
> >>
> >>Scotty
> >>
> >>
> >>
> >> > Priscilla
> >> >
> >> >
> >> >>thanx,
> >> >>
> >> >>skin-e
> >> >>
> >> >>_________________________________
> >> >>FAQ, list archives, and subscription info:
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> >> >
> >> > ________________________
> >> >
> >> > Priscilla Oppenheimer
> >> > http://www.priscilla.com
> >> >
> >> > _________________________________
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> >>
> >>----------------------------------------------------------
> >>Scott Nelson - Network Engineer
> >>Wash DC +1202-270-8968 & +1202-352-6646
> >>Los Angeles +1310-367-6646
> >>mailto:[EMAIL PROTECTED]
> >>http://www.bnmnetworks.net
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>
>----------------------------------------------------------
>Scott Nelson - Network Engineer
>Wash DC +1202-270-8968 & +1202-352-6646
>Los Angeles +1310-367-6646
>mailto:[EMAIL PROTECTED]
>http://www.bnmnetworks.net
>
>PGP Public Key:
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>----------------------------------------------------------
>
>"The better the customer service, the sooner you get to speak
>with someone who can't help you."
>----------------------------------------------
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