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- Ethernet Packet Driver MLID, v1.01
-
- Introduction
- ------------
-
- PDEther.Exe is an ODI to Packet Driver adaptor. It provides an ODI
- interface for an arbitrary Ethernet Packet Driver. This allows ODI
- access to any Ethernet board which has a Packet Driver and also
- allows Packet Driver applications and ODI applications using
- different network layer protocols to coexist in the same DOS system.
-
- Using PDEther
- -------------
-
- In Packet Driver terms, PDEther is an application. In ODI terms, it
- is a LAN driver, also know as a "link driver" or "MLID". The loading
- sequence will be something like this:
-
- 1. Load the packet driver supporting your card.
- 2. Load LSL.
- 3. Load PDEther.
- 4. Load IPXODI, NetX, and/or other ODI applications.
-
- Like all good ODI modules, PDEther reads Net.Cfg for configuration
- information. The next section of this document describes PDEther's
- requirements for Net.Cfg, including a description of PDEther's Link
- Driver section.
-
- Net.Cfg
- -------
-
- You must configure at least one 1514 byte ODI receive buffers in the
- Link Support section of the Net.Cfg file using the Buffers keyword:
-
- Link Support
- Buffers 4 1514
-
- A few extra buffers may allow PDEther to handle congested conditions
- better. If no buffers are allocated or they are not 1514 bytes long,
- PDEther prints a warning message.
-
- Some packet drivers will work with smaller buffer sizes, but it is
- difficult to tell which will and which won't. For that reason, i
- recommend always using 1514 byte ODI buffers but, on the other hand,
- PDEther will try to muddle through even if 1514 byte buffers are not
- available.
-
- Your Net.Cfg file should also contain a Link Driver section for
- PDEther. Such a section begins with the unindented text "Link
- Driver PDEther". As is normal in the Net.Cfg file, the section
- continues until the next unindented line. (In other words, all lines
- in the Link Driver section should be indented by one or more spaces
- or tabs.)
-
- PDEther ignores case, extra white space, and comments when reading
- Net.Cfg. Comments begin with "#" and continue to the end of the
- current line.
-
- The Link Driver section of the Net.Cfg file supports three keywords:
-
- INT <hex interrupt>
-
- The INT line specifies the software interrupt of the Packet
- Driver the MLID should use. The value is a hex number
- between 60 hex and 80 hex. The number may optionally be
- preceeded by "0x" to indicate a hex number, but the number is
- read in hex whether or not the "0x" is present. If PDEther
- sees no INT line, it uses the Packet Driver at software
- interrupt 60 hex.
-
- FRAME Ethernet_II
-
- This is just the standard frame type parameter that all MLIDs
- support. Since this driver only supports Ethernet, only
- "Ethernet_II" is accepted. For the same reason, this line is
- entirely optional.
-
- PROTOCOL <protocol name> <hex E-type> Ethernet_II
-
- This is the standard protocol identification line. The
- protocol name (case insensitive) identifies the protocol
- to LSL. E-type is a hex number indicating the Ethernet type
- value for this protocol. (Again, it may be preceeded by "0x",
- but it is always interpretted in hex.) The media name is
- Ethernet_II. Again, Ethernet_II is the only media supported,
- so contrary to standard Net.Cfg practice, specifying
- Ethernet_II is optional.
-
- ===>>> *ALL* protocols this driver is to support must be specified
- in the Link Driver section, since the MLID must be able to
- tell the Packet Driver specifically about any protocols the
- MLID wants to receive. There is one typical Novell exception:
- IPX is set up automatically if it is not specified explicitly.
-
- On the other hand, do *not* specify protocols which the
- packet driver is supporting directly. This will make PDEther
- take control of those protocols, so your packet driver
- application won't be able to use them.
-
- Here are some example lines. By the way, if you are using an ODI
- TCP/IP protocol stack, you will need these protocol lines in your
- Net.Cfg file to tell PDEther about the IP protocols.
-
- Int 60
- Frame Ethernet_II
- Protocol IP 800 Ethernet_II
- Protocol ARP 806 Ethernet_II
- Protocol RARP 8035 Ethernet_II
-
-
- Loading a Packet Driver
- -----------------------
-
- PDEther supports the 1.09 Packet Driver specification. I assume
- later Packet Driver interface versions will also work. In addition, I
- have no particular reason to think it wouldn't work on older Packet
- Driver interfaces, since it uses no features flagged as new in 1.09,
- but i've only been using 1.09.
-
- Releases of the Clarkson Packet Drivers since release 7 support
- version 1.09 of the spec. Release 7 was also the first Packet
- Drivers which support the "raw" 802.3 IPX framing convention via "-n"
- switch described below. At this time of this writing, the latest
- Clarkson release is release 9.
-
- The details of loading a Packet Driver should be provided with your
- Packet Driver and are beyond the scope of this document. Generally,
- you tell the packet driver which software interrupt to use and how to
- talk to the hardware through parameters on the command line.
-
- Standard Packet Drivers take *all* input in decimal by default,
- although you may specify hex by using the "0x" prefix. This is
- counter-intuitive, since almost all parameters to any packet driver
- are numbers which make little or no sense in decimal.
-
- Standard Packet Drivers take the software interrupt as the first
- argument. The software interrupt *must* agree with the INT parameter
- in the Link Driver PDEther section of the Net.Cfg file. (But again,
- remember to prefix the packet driver parameter with "0x". The INT
- parameter in Net.Cfg is always interpreted as a hex number.)
-
- If your network uses the popular "Ethernet_802.3" frame type (the
- illegal Novell "raw" 802.3 framing type) for IPX traffic, give the
- Packet Driver the "-n" switch to get that framing for IPX traffic.
- This tells the Standard Packet Drivers to send IPX traffic in the
- "raw" 802.3 format. The "-n" switch does not affect other
- protocols. The default IPX protocol ID (8137 hex) *must* be used so
- the Packet Driver can identify IPX packets.
-
- Note that when using the "-n" switch, you continue to specify
- "Ethernet_II" in the Net.Cfg file; you do *not* indicate the frame
- type Ethernet_802.3 as you would in a normal ODI Link Driver. The
- "raw" 802.3 framing is handled by the Packet Driver without PDEther's
- knowledge.
-
- Here's an example of a typical packet driver command line which loads
- a Packet Driver on software interrupt 60 hex to support an NE2000
- ethernet card on hardware interrupt 5, port 340 hex, using normal
- Ethernet framing.
-
- ne2000 0x60 5 0x340
-
- To load the same Packet Driver but have it send IPX packets using
- Novell's default Ethernet_802.3 framing instead of the more proper
- Ethernet_II, use a command line like this:
-
- ne2000 -n 0x60 5 0x340
-
- Limitations
- -----------
-
- Although the Clarkson Packet Drivers now support 802.3/802.2 and
- 802.3/802.2/SNAP, this MLID does not support those two framing
- types.
-
- Some of the less important features of the Packet Driver are not
- supported. For example, it cannot deal with a Packet Driver
- supporting multiple boards.
-
- If you are using PDEther under applications other than IPX, each
- protocol (except IPX) must be explicitly listed in the PDEther's Link
- Driver section. Although "normal" from the point of view of the
- Net.Cfg design, it is quite abnormal in practice. Novell's TCPIP for
- ODI, for example, will automatically add the TCP/IP protocol IDs if
- they are not present, but THIS DOES *NOT* HELP PDEther which must
- find them in its section of Net.Cfg. This is unfortunate. Failure
- to list the protocols in the Net.Cfg file is not a detectable error
- so all the software will be satisfied, but no arriving packets will
- be delivered to IP.
-
- Bibliography
- ------------
-
- FTP Software, "PC/TCP Packet Driver Specification", version 1.09,
- September, 1989.
-
- Novell, "Open Data-Link Interface Developer's Guide for
- NetWare DOS Workstation Drivers", Revision A, 30 January 1991.
-
- Conclusion
- ----------
-
- Let me know if you have any problems.
-
- don provan
- donp@novell.com
- 11/1/91
-
-