ljm@TWG.COM (Leo J McLaughlin) (09/27/89)
Ted, >Thanks for all of your comments. If you have more please keep them coming! >1) If you were to select a NOS that could interoperate with hosts >supporting the major operating systems (UNIX, VMS, VMS, VM, DOS, OS/2, >Finder), which one would you select? Obviously our TCP/IP based PathWay family of products, but then again I do get a pretty steep price discount. >2) Where can I get my hands on the LAN Manager specification? From Microsoft (but you won't like the price tag). >3) Please clarify my understanding of LAN Manger... LAN Manager is an set of operating system extensions designed to look similar over many differnet operating systems -- it is not to be understood as part of a protocol suite or as living at (or over) any particular layer of a protocol suite. Basically, it provides a socket-like API (names pipes), a NetBIOS-like API, and functions to handle resource sharing and management. Those particular LAN Manager implementations which are LAN Manager for DOS and OS/2 provide the additional functionality of supporting the LAN Manager API over multiple protocol stacks over (given NDIS support in the protocol stacks themselves) one or more network interface cards. >After going through this confusing scenerio, it sounds like the LAN >Manager Spec. should just specify all seven layers of the protocol >stack! That would, I think, rid some of the confusion... Again, LAN Manager is an operating system concept, not a protocol concept. It says nothing about how a mythical LAN Manager developer might provide access to '\\machinename\pipe\pipename'; it says that for an operating system to provide LAN Manager support is to allow an application to use the twenty or so pipes functions on the resource specified by that string. >On the other hand, why did we need LAN Manager when we have a tcp/ip based >protocol stack [I would REALLY appreciate any comments on this]? Remember that the idea of LAN Manager was born long before networking companies developed products which allowed workstations on proprietary LANs access to TCP/IP networks. However, if your site was so lucky as to start out with TCP/IP for its micro computers, then the proprietary protocol coexistance issue is resolved as well as the the common API issue. For you the magical promise of LAN Manager already exists. enjoy, leo j mclaughlin iii The Wollongong Group ljm@twg.com
jbvb@VAX.FTP.COM (James Van Bokkelen) (09/27/89)
One major problem with LAN Manager is that its only programming interfaces are the "Named Pipes" and Netbios NCB interfaces. There is no defined method of getting at an unadulterated transport protocol connection; whether the transport is XNS or TCP or OSI the lowest you can get is a Netbios session. So the LAN Manager "standard" can't talk to anything except other LAN Managers or Netbioses without vendor extensions (which won't be standard unless/until the market produces one). Furthermore, there is no defined interface to the redirector, so any filesystem sharing you do uses SMB. No Netware, NFS, RFS or RVD under LAN Manager, unless you want to hide a kludge that translates SMB to another protocol below the pseudo-NETBIOS layer (not if I can avoid it). In terms of layering, NETBIOS is more or less session-layer by itself. It can be defined to use different transport layers (TCP, XNS, OSI, DECNet, etc). Transport layers can use different MAC layers, but it is hard to make a particular instance of a transport layer independent of the MAC layer below it; Ethernet uses ARP one way, 802.5 uses it another, MTUs and headers differ, bit orderings differ. Neither NDIS, ASI, Packet Driver or OLI provide real MAC-layer independence; instead they provide demux support and independence from details of individual Ethernet (or whatever) cards. IBM's ASI interface is very 802.5-specific, but the others aren't specific to one MAC layer. Fundamentally, LANManager is Microsoft's idea of what a NOS should look like, complete with solutions for all the problems they felt were important, tailored for the operating systems they care about. As such it is different from SNA/SAA (IBM's idea), DECNet (DEC's idea), Netware (Novell's idea), etc. etc., but no less proprietary and narrowly-focussed. The open standard you would probably prefer doesn't really exist yet, but Apollo/HP (with NCS), Sun (with their RPC and Yellow Pages) and the OSI people are all heading that way. James B. VanBokkelen 26 Princess St., Wakefield, MA 01880 FTP Software Inc. voice: (617) 246-0900 fax: (617) 246-0901
mead@UHURA.CC.ROCHESTER.EDU (Ted Mead) (09/28/89)
> There is no defined method of getting at an unadulterated transport protocol > connection; whether the transport is XNS or TCP or OSI the lowest you > can get is a Netbios session. So the LAN Manager "standard" can't > talk to anything except other LAN Managers or Netbioses without vendor > extensions (which won't be standard unless/until the market produces > one). So, what tranport protocol does LAN Manager use? How does SMB fit in with LAN Manager? Thanks, Ted
jbvb@VAX.FTP.COM (James Van Bokkelen) (09/28/89)
Date: Wed, 27 Sep 89 17:07:28 -0400 From: Ted Mead <mead@uhura.cc.rochester.edu> > There is no defined method of getting at an unadulterated transport protocol > connection; whether the transport is XNS or TCP or OSI the lowest you > can get is a Netbios session. So the LAN Manager "standard" can't > talk to anything except other LAN Managers or Netbioses without vendor > extensions (which won't be standard unless/until the market produces > one). So, what tranport protocol does LAN Manager use? How does SMB fit in with LAN Manager? LAN Mnager uses whatever transport protocol the LAN Manager OEM (or the end user) chooses to add to his PROTOCOLS.INI file, assuming that it presents a standard Netbios-style NCB interface as appropriate for the operating system in use. It doesn't care if it is OSI or TCP or XNS, it uses its' own constructs (Server Message Blocks, familiar to those of you who've investigated MS/Net or the PC LAN Program) on top of Netbios "sessions". James B. VanBokkelen 26 Princess St., Wakefield, MA 01880 FTP Software Inc. voice: (617) 246-0900 fax: (617) 246-0901
ljm@TWG.COM (Leo J McLaughlin) (09/29/89)
>One major problem with LAN Manager is that its only programming >interfaces are the "Named Pipes" and Netbios NCB interfaces. There is >no defined method of getting at an unadulterated transport protocol >connection; whether the transport is XNS or TCP or OSI the lowest you >can get is a Netbios session. So the LAN Manager "standard" can't >talk to anything except other LAN Managers or Netbioses without vendor >extensions (which won't be standard unless/until the market produces >one). Well, yes and no. As it happens, Microsoft's LAN Manager for DOS and LAN Manager for OS/2 use names pipes to speak to NetBIOS over NetBEUI. However, that part of the LAN Manager API which constitues names pipes is a perfectly reasonable (well mostly reasonable) transport API. enjoy, leo j mclaughlin iii The Wollongong Group ljm@twg.com