In the article on Future Directions it says RTI has determined that there is no way to provide support for TCP/IP under DOS. The included chart shows support for Novell 5.0 TCP/IP to be limited to OI 3.7 and above.

We have been running AREV with Windows 95 workstations and a Windows NT server using TCP/IP for some time. Can someone explain why it is possible to do this with NT, but not Novell?

There are three possible ways that Advanced Revelation and OpenInsight can utilize TCP/IP:

1. The Operating System file services (int 21h) can be mapped to a Network File System; in these cases, the file I/O requests are handled by a VxD whose only job is to communicate the request to (and the result from) a "file server". If the work-station is communicating with that server via TCP/IP, then these I/O requests will be transmitted between the workstation and the server (and potentially routers etc. in between) using the TCP/IP protocol. This is all "behind the scenes" as the application (for example, the NPP using its "local mode") will not know or care that these requests are being transmitted via TCP/IP.

2. Some higher-level communications protocols are not transport protocols, and therefore require a lower-level protocol such as TCP/IP in order to communicate between two computers. In our case, we see this when using Microsoft's proprietary Named Pipes protocol to communicate between the NPP driver and the LH/NT Service. Again, this may use the TCP/IP protocol "behind the scenes" and the driver neither knows or cares.

3. There is a standard Application Programming Interface for TCP/IP called sockets. (TCP/IP itself is not a programming interface – it is just a data transfer specification.) Sockets are a fairly low-level means to use TCP/IP to communicate between (or among) processes and machines. We do use the sockets API (called WinSock) from the new LH/TCPIP driver in order to communicate with the new version of the LH/NT Service and the brand new jLH/Server. In this case, the driver does know that it is using the TCP/IP protocol … and it is using it as directly as is possible. The WinSock API used by the LH/TCPIP driver is available as a standard part of all contemporary versions of the Windows Operating Systems. Our Windows product, OpenInsight, required slight (but very deep) modifications in order to use the LH/TCPIP driver due to the architecture of the WinSock library. Unfortunately, we cannot easily port these changes back to previous versions, so the LH/TCPIP driver will only work with OpenInsight vers

ions 3.7 and later. Furthermore, since there is no standard socket implementation available as part of DOS, we are unable to provide a version of the LH/TCPIP driver for Arev.

Cameron,

Thanks for the quick response, and I believe that I understand your points.

Your response specifically mentions the NT and the Java LH engines. In a NetWare environment, however, I am more interested in the NLM. As I understand it, the NLM still way out-performs the Java engine; and our own experience is that the NLM is at least 3 to 4 times faster than the NT Service on comparable equipment.

Many of our customers are interested in NetWare 5.0 due to the use of TCP/IP and they would like to move to a pure IP environment. Right now they have to continue to use IPX for the NLM.

What is the direction regarding the use of TCP/IP with the NLM, and does it pose the same problems that you described for NT and the Java engine?

Dan

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