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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

151.0. "Using DECstation 5000/200 as DECbridge 5000s?" by ZPOVC::HWCHOY (It must be Thursday.) Sun Oct 07 1990 06:43

    
    
    	+--------------+
        |              |
        | DECconc 500  |
        +--------------+
           |         |
           |         +----------------+
           |                          |
    +-------------+           +------------+        
    | DECstation  |           | DECstation |
    | 5000/200    |           | 5000/200   |
    +-------------+           +------------+
           |                          |
    o==================o      o=========================o
    ethernet A				ethernet B
    
    
    Consider a TURBOchannel based DEcstation 5000/200 equipped with an
    FDDIcontroller 700. Would such a configuration allow it to perform
    'bridging' function like that of a DECbridge 500?
    
    My gut feel is NO. And would venture to guess that it is due to a lack
    of FDDI-Ethernet translating capability. Am I right?
    
    However, it would be able to do IP-routing (as stated in Sales Update
    for FDDI-FDDI IP-routing).
    
    Another question would be, if it can do IP-routing in this manner, how
    about DECnet routing?
    
    thanx for any comments,
    Heng-Wah

T.R	Title	User	Personal Name	Date	Lines
151.1	DECnet routing in Phase V	AKO569::JOY	Get a life!	`Tue Oct 09 1990 13:30`	12
	Heng-wah, The DS5000 will be able to function as a DECnet router when FDDI support is available for DECnet. Right now that means waiting for Phase V, but there is some discussion that there may be a Phase IV driver written since Phase V is so late. Also, when Phase V is available, it will be able to do OSI routing as well. The DS5000 wouldn't be able to do "bridge" functions such as flitering or address translation unless some special software was written for it. Debbie
151.2	DECnet-Ultrix is End Node only	EVTAI1::GROSSETETE		`Tue Oct 09 1990 15:41`	10
	Hi, The DS5000 is an Ultrix system (RISC based), I don't think there is any plan to produce a DECnet-Ultrix Phase V with routing capability, so you'll be able to just use it as an IP router, not DECnet (Phase IV on DECnet-Ultrix is also an End Node implementation) Regards Patrick
151.3		WILE::thomas	The Code Warrior	`Tue Oct 09 1990 17:08`	1
	There is no routing support in DECnet-ULTRIX (Phase IV or Phase V).
151.4	The memory is the first thing to go....	AKO569::JOY	Get a life!	`Wed Oct 10 1990 11:57`	5
	re; .2, .3 Oops....sorry, I forgot about the non-routing capability of DECnet ULTRIX. I stand corrected. Debbie
151.5	thanx	ZPOVC::HWCHOY	It must be Thursday.	`Wed Oct 10 1990 12:55`	9
	Right! That's the reason why it is stated that the DS5000 with two FDDI controllers can act as an IP-router, and not DECnet. thanx for all the response rgds, hw ps: Joy, I've forwarded your note regarding UEG's bombshell. Quite a lot of people is might unhappy.
151.6	Fragmentation under DECnet	BERN01::DEY	Walter Dey, EIS, Berne Switzerland	`Thu Oct 11 1990 11:58`	18
	re.1 >> Right now that means waiting for Phase >> V, but there is some discussion that there may be a Phase IV driver >> written since Phase V is so late. Also, when Phase V is available, it >> will be able to do OSI routing as well. If we have a VAX with FDDI interface directly attached to WC, running DECnet, and doing e.g. file transfer to a DECnet Ethernet station connected via a 10/100 Mbit bridge. How is the fragmentation of the max. 4500 Byte FDDI frames to Ethernet frames handled , Ph IV, Ph V? I hope not, that we will send Ethernet max packet size over FDDI ring ? We have a nice solution for IP, but what about DECnet ? Walter.
151.7	Phase IV = 1500 bytes	AKO569::JOY	Get a life!	`Thu Oct 11 1990 14:29`	8
	Write now with Phase IV, we will keep the packet size to 1500 bytes on FDDI. We could do this with Phase V as well, but it would seem to defeat some of the advantages of FDDI and OSI. I would guess that when Phase V comes out, we will come up with some sort of fragmentation scheme to support this. Anyone else know for sure? Debbie
151.8	Phase V has to be 4500 bytes	KONING::KONING	NI1D @FN42eq	`Thu Oct 11 1990 18:32`	5
	It's clear that for Phase V we will have to do the same thing as was done for IP. For Phase IV that is, unfortunately, not an option since there is no such thing as fragmentation for Phase IV. paul
151.9		MIPSBX::thomas	The Code Warrior	`Thu Oct 11 1990 23:16`	1
	But will the bridges fragment ISO IP frames?
151.10		BERN01::DEY	Walter Dey, EIS, Berne Switzerland	`Fri Oct 12 1990 10:15`	15
	Paul >> It's clear that for Phase V we will have to do the same thing as was >> done for IP. For Phase IV that is, unfortunately, not an option since >> there is no such thing as fragmentation for Phase IV. As I understand, we have only Fragmentation/Segmentation at Transport(NSP)level in Ph IV, in Phase V we have Fragmentation also at Network layer. Does this mean, that the FDDI 100/10 Mbit will do in addition a fragmentation on the datalink layer ? Is there a corresponding OSI standard ? Or will we have a propietary solution ? Regards Walter.
151.11	It isn't datalink fragmentation	KONING::KONING	NI1D @FN42eq	`Fri Oct 12 1990 11:43`	6
	The transport layer process is called "segmentation". "Fragmentation" is what the network layer does. Fragmentation as done by bridges is the same network layer algorithm. If you want to, think of it as having a small piece of the network layer in the bridge. paul
151.12		MARVIN::COBB	Graham R. Cobb (Wide Area Comms.), REO2-G/H9, 830-3917	`Tue Oct 16 1990 08:26`	7
	.9> But will the bridges fragment ISO IP frames? Good question. If, by then, we had bridge/routers which could route (including fragmentation as necessary) the OSI (and Phase IV and IP) frames, would anyone still want bridging+fragmentation for them? Graham
151.13	Obviously...	KONING::KONING	NI1D @FN42eq	`Mon Oct 29 1990 17:58`	3
	Because they have the bridges already installed, of course. paul
151.14		MARVIN::COBB	Graham R. Cobb (Wide Area Comms.), REO2-G/H9, 830-3917	`Tue Oct 30 1990 15:31`	13
	My question wasn't "why would anyone want...?" but "would anyone want...?". .13 is a reason people might want bridging when routing is available, I was looking for feedback from the field as to whether their customers do (or will) want that. Also, I would like any information as to whether there are any other reasons. I.e. if the cost to the customer of routing vs. bridging was $0 (e.g. they already had the hardware and wanted to decide whether to run routing or bridging on it), would anyone want bridging? Any feedback will be appreciated. Graham
151.15	Bridging/Routing	NSCRUE::KNIGHT		`Fri Nov 09 1990 18:42`	22
	re: .12, .14 Graham, Perhaps if you elaborated a bit on specific scenarios for connections it would be easier to provide feedback on your bridging/routing questions. I'll take a stab at it: I believe there will be a number of installations using Ethernet as the backbone and FDDI on the subnets/workgroups. Bridging would be quite reasonable here for the relatively infrequent trafic between workgroups. Likewise, if FDDI is the backbone, and separate FDDI workgroups are linked to the backbone. The latter configuration is one which would be much appreciated by one customer who has a huge campus with three major clusters several miles apart. Another issue is specific protocols (LAT??) which might be adversely affected by routing, but are happy being bridged. Sounds like you are working on "1066", eh? Regards, Paul Knight
151.16		WIKKIT::WARWICK	Trevor Warwick	`Tue Nov 13 1990 08:40`	11
	I think what Graham was asking was as follows: If there were a box that could route DECnet/OSI and IP traffic (according to the appropriate specs), and bridge anything else (LAT, SCS etc.), would any customer have a requirement to be able to turn off the Routing for either DECnet or IP, and bridge it instead ? Assume that there was no performance difference between rouging and bridging in this hypothetical box. Trevor
151.17		KONING::KONING	NI1D @FN42eq	`Tue Nov 13 1990 12:05`	8
	Certainly IF such a product existed, most customers would want to use its routing capabilities. I suspect an occasional user would elect to bridge protocols even though they could be routed, because of the fact that it takes more network management to set up a routed network than a bridged one. But the advantages of routing, where available, generally outweigh that issue. paul
151.18	DS5000 as IP router:performance info	SWAM3::MARCUS_RI		`Wed Dec 12 1990 22:13`	25
	Hi to anyone, I'm a Sales Rep. out here in sunny California, and I've been bouncing all over this wonderful company of ours trying to get an answer to a question from one of my customers. Is there anybody out there that can tell me what the performance of a DECstation or DECsystem 5000 will be when it is used as an IP router? MY customer is purchasing 4-6 DECstation 5000-200PXG'S. Due to the large image files that they will be dealing with, their intention is to connect them via FDDI. They also have several DECstation 3100's on an Ethernet, talking TCP/IP. They want to tie these two networks together with the aforementioned hardware. Any performance information on this configuration that you can provide me would be greatly appreciated. Since I am really a VAXnotes novice and don't do well with all these commands, please send your replies to: All-in-One: Rich Marcus @LAO VMSmail: SWAM3::MARCUS_RI Thanks in advance. (Boy, I really hope this works!!!)