9 Apr 1995

Adding LAN Support

The Internet Connection supplied with the Bonus Pak for Personal Warp contains only support for dial-in access using SLIP (and PPP with the "PPP Update"). Compatible LAN support will be provided in a future LAN Client version of the Warp family. LAN Client will simply repackage and slightly upgrade some code that is already available. If you are unable to wait, you can install LAN support using disks from IBM LAN Server 4.0.

It doesn't make sense to buy a Server just to get the client piece. However, LS 4.0 is a very nice, very fast file server and many people will already have a copy. There are also a number of more exotic products (Anynet/2, DCE) that have the same code. Everyone else may find it a lot cheaper to wait for the LAN Server to be offered.

You don't really need LS itself, but rather a component named MPTS that is distributed with it. MPTS (Multi-Protocol Transport Services) is the latest version of a sequence of OS/2 LAN support components with names like LAPS and NTS/2. The terms "MPTS" and "MPTN" are often used interchangeably to refer to the component. Where it matters, MPTS.EXE is a utility program and \MPTN is the directory into which it installs some files.

If PCLT ever becomes more formalized, the next section will be on the Drake Test. There are a handful of interrelated Three and Four Letter Acronyms (TFLAs) that always confuse people. It is not safe to try to bypass these issues.

OS/2 LAN support is based on NDIS 2.x (the second generation of the MS-3Com Network Driver Interface Specification). DOS drivers are 16-bit NDIS 1.x, and Chicago/NT drivers are 32-bit NDIS 3.x. OS/2 Device Drivers still support a 16-bit interface, even though the whole system supports 32-bit code, so it is reasonable that the 2.x release number fits right between DOS and NT.
Novell has its own ODI stuff. ODI does the same thing as NDIS, but its different. The only thing going for ODI is the large market share that Novell enjoys. TCP/IP and all the other IBM stuff (SNA, DCE, ...) works through NDIS. Novell has been unable to deliver working code for OS/2, NT, Chicago, or any system more complicated than DOS. ODI may be a bit faster, but since it doesn't work this is not necessarily an advantage.
In previous years, IBM tried to nickel and dime customers by packaging only the subset of LAN support needed to run any given product. LAN Server had no TCP/IP, and the TCP/IP product had no NETBIOS support. To run NETBIOS over TCP/IP required a third optional product. This was the problem with LAPS and NTS/2.
Microsoft is now bundling all its support in with WFWG, Chicago, and NT. NETBEUI has problems in large networks, and IBM needs a standard NETBIOS over TCP/IP to overcome them. To keep LAN Server 4.0 competitive, IBM had to add minimal TCP/IP protocol support into that product.
There is also the larger IBM Communications Blueprint. This larger strategy breaks networking down into three independent interfaces. The user can choose any type of connection (Ethernet, Token Ring, ISDN, or modem). Separately, the user can choose any type of Network based on how much management and complexity is required (NETBEUI is simple but local, TCP/IP is harder, SNA is hardest but best controlled). At the top, the programmer chooses any programming interface (the "Sockets" subroutines from Unix, the CPIC subroutines from SNA). The Blueprint says that all combinations of subroutines, networks, and adapters should work.
MPTS reflects the OS/2 LAN support for the Communications Blueprint. It provides support for NETBIOS, TCP/IP, and SNA. It includes the NETBIOS over TCP/IP support previously sold as a separate product. It also include the Sockets subroutine libraries previously sold as part of the TCP/IP Programmer's Kit.
To get CPIC and other SNA support over MPTS, it is still necessary to purchase the Communications Manager. To run SNA over TCP/IP, one needs the Anynet/2 product. To get programming interfaces other than Sockets, one needs other products (DCE Client, TCP/IP Programmers for Sun RPC, X-Windows Client). However, MPTS by itself is enough to support LAN access from the Warp Internet Connection programs and to provide the most popular Internet programming interface.

For MPTS to work well with the Internet Connection, it should be at level WR08000 or later. The files will be dated Sept. 94 or later. The version of MPTS distributed on DEVCON (files dated Aug 94 or earlier) are unable to coexist smoothly with the support provided with the Warp Bonus Pak.

Before and After

The Warp Internet Connection was installed into a directory named \TCPIP on your hard disk. MPTS will create two additional directories. \IBMCOM will contain the NDIS 2.x code. \MPTN will contain the additional multiprotocol support.

After installing Warp and the Bonus Pak and before installing MPTS, the CONFIG.SYS file should include statements like:

DEVICE=g:\tcpip\bin\inet.sys
DEVICE=g:\tcpip\bin\ifndisnl.sys
DEVICE=g:\tcpip\bin\vdostcp.vdd
DEVICE=g:\tcpip\bin\vdostcp.sys
RUN=g:\tcpip\bin\cntrl.exe
RUN=g:\tcpip\bin\vdosctl.exe

INET, IFNDISNL, and CNTRL are the core of the TCP/IP protocol. The other three drivers provide TCP/IP access for DOS and Windows programs. MPTS also contains its own copies of the three core drivers. INET and CNTRL are pretty much the same programs in the Bonus Pak and in MPTS. IFNDISNL was a dummy placeholder that has to be upgraded to the real MPTS code.

MPTS is distributed on three diskettes or on CDROM. It is installed and configured with the MPTS.EXE utility. After it has been installed, CONFIG.SYS will have been changed.

Lines added near the front:
DEVICE=G:\ibmcom\LANMSGDD.OS2 /I:G:\ibmcom
DEVICE=G:\ibmcom\PROTMAN.OS2 /I:G:\ibmcom

What is left of the Bonus Pak drivers:
DEVICE=g:\tcpip\bin\vdostcp.vdd
DEVICE=g:\tcpip\bin\vdostcp.sys
RUN=g:\tcpip\bin\vdosctl.exe

Lines added at the end:
CALL=G:\ibmcom\PROTOCOL\NETBIND.EXE
RUN=G:\ibmcom\LANMSGEX.EXE
DEVICE=G:\MPTN\PROTOCOL\MPTN.SYS
DEVICE=G:\MPTN\PROTOCOL\LIPC.SYS
DEVICE=G:\MPTN\PROTOCOL\INET.SYS
DEVICE=G:\MPTN\PROTOCOL\IFNDIS.SYS
RUN=G:\MPTN\BIN\CNTRL.EXE /P mptn_os$ mptn_in$
CALL=G:\OS2\CMD.EXE /Q /C G:\MPTN\BIN\MPTSTART.CMD
DEVICE=G:\IBMCOM\MACS\ELNK3.OS2

Disk letters will vary. Additional lines might be added if NETBIOS is installed to support the LAN Server 4.0 Redirector. The last line for ELNK3 supports a 3Com Etherlink III adapter card and will be different for other types of LAN cards.

As before INET, IFNDIS, and CNTL are the core of the TCP/IP part. MPTS replaces the Internet Connection drivers with its own code. MPTS doesn't itself provide support for DOS/Windows programs, but the three drivers from Internet Connection that are not replaced (two VDOSTCP modules and VDOSCTL) provide that support. The combination of Internet Connection (installed first) and MPTS (installed on top of it) provide fairly complete coverage.

PROTMAN manages the NDIS stuff. ELNK3 is an example of a LAN hardware driver. LIPC provides a high performance connect between programs on the same machine (Local Inter-Process Communications) that can be easily extended through the LAN to other machine.

Information needed to configure NDIS components (hardware parameters for the Ethernet Card, NETBIOS limits, etc) are stored in \IBMCOM\PROTOCOL.INI. Generally, this file contains nothing related to the Internet.

TCP/IP configuration, however, is a bit more confusing. MPTS is designed to provide TCP/IP support to connect LAN Server 4.0 clients and servers together even without Internet access. The Warp Internet Connection from the Bonus Pak provides Internet access through the modem without a LAN. When you throw the two together, there is some overlap.

One user installs Warp on a laptop computer in the office. There is an Ethernet "credit card" PCMCIA adapter in the machine, so MPTS is also installed. Both the Bonus Pak and the MPTS panels are configured with information about the office environment. The laptop will now work both from home (over the modem) and at the office (over the LAN) because both Internet Connection and MPTS were configured with the same parameters.

Another user has a desktop machine with a modem and a LAN configuration. Most of the time the user connects to the office network over the LAN. Occasionally, the user wants to access a remote network over the modem. In this case, MPTS will be configured with the local office parameters, while the Internet Connection will be configured with information about the remote network. Getting this mess to work requires careful handling.

SET ETC=G:\TCPIP\ETC

The ETC environment variable, normally set in CONFIG.SYS, points to the directory from which Internet client application programs expect to get their information. To find a server machine from its name, the Internet support subroutines will look in this directory for the RESOLV file that designates a domain name server or for a HOSTS table that lists names and IP addresses. The mail, news, and other utilities save their information in this directory.

The IP number of the LAN adapter and routing information to the outside world are established by commands. MPTS configuration creates a set of commands to be executed during initialization and stores them in \MPTN\BIN\SETUP.CMD:

route -f
arp -f
ifconfig lan0 130.132.57.244 netmask 255.255.255.0 metric 0 mtu 1500 broadcast 130.132.57.255
route add default 130.132.57.1 1

A sharp eyed reader may remember that the same statements were generated for SLIP/PPP connections explicitly in a REXX login script or implicitly with the "Dial Other Internet Providers" utility. The IFCONFIG statement tells TCP/IP that the Ethernet adapter (LAN0) has IP address 130.132.57.244. It is connected to the network of all machines with addresses 130.132.57.*. The ROUTE statement says that the machine 130.132.57.1 is a Gateway to the rest of the world.

This arrangement is based on the original Unix design for Internet support. Unix machines are sometimes connected to more than one network, and a Unix box can act as a gateway between two networks. The information about an individual LAN adapter was regarded as more changeable that the information about the network as a whole. Thus ETC configures information (like the Name Server address) that is regarded as global, while IFCONFIG and ROUTE change dynamic routing tables.

The MPTSTART statement in CONFIG.SYS configures the address and routing gateway for the LAN adapter. To change later on to use SLIP, one should use "ifconfig lan0 down" to disable the LAN adapter, then run the standard login script or "Dial Other Internet Providers" utility. Once the remote connection is established, another IFCONFIG will be issued for the "sl0" SLIP/PPP line and another ROUTE command will establish a new Gateway.

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