IPX/SPX-compatible Protocol

The Microsoft Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) – compatible protocol (nwlink.vxd) supports the 32-bit Windows Sockets 1.1 programming interface, so that any Win32-based Windows Sockets 1.1 application can run on IPX/SPX with Windows 98. (There are no 16-bit Windows Sockets applications using IPX/SPX.)

The IPX/SPX-compatible protocol can be used by Client for NetWare Networks to communicate with NetWare servers or computers running File and Printer Sharing for NetWare Networks.

This protocol can also be used by Client for Microsoft Networks to communicate with computers running Windows for Workgroups 3.11 or Windows NT that are also running IPX/SPX.

The IPX/SPX-compatible protocol uses the nwnblink.vxd module to support computers that use NetBIOS over IPX and to support the NetBIOS programming interface. This protocol can also use NetWare servers configured as routers (and other IPX routers) to transfer packets across LANs.

Configuring the IPX/SPX-compatible Protocol

The Microsoft IPX/SPX – compatible protocol is installed automatically when Client for NetWare Networks is installed. You can also install this protocol to support other network clients, including Client for Microsoft Networks.

To install the IPX/SPX-compatible protocol

In Control Panel, double-click Network, and then click Add.
In the Select Network Component Type dialog box, click Protocol and then click the Add button.
In Manufacturers, click Microsoft, and then in Network Protocols, click IPX/SPX-compatible Protocol, and then click OK.
Click OK. Setup copies the files you need.

When you install the IPX/SPX-compatible protocol, Windows 98 automatically detects and sets appropriate values for the frame type, network address, and other settings. However, in some cases you might need to configure settings for this protocol manually.

To configure the IPX/SPX-compatible protocol

In Control Panel, double-click Network.
Double-click the instance of IPX/SPX-compatible Protocol that is bound to your network adapter.
Note
If the computer has multiple network adapters, the list will contain an instance of the IPX/SPX-compatible protocol for each network adapter. You must configure each adapter with its own settings. You can only have four instances of IPX/SPX on your system, so if you have more than four adapters are installed, you should bind IPX/SPX only to the adapters that will use this protocol.
Click the Advanced tab.
Most values have correct defaults in typical installations. If you need to change a value for a particular purpose, select the item in the Property list and specify a setting in the Value list based on the information in the Table 15.10.

Table 15.10 IPX/SPX configuration values

Property	Value

Force even-length IPX packets	Enabled only for Ethernet 802.3 on monolithic implementations that cannot handle odd-length packets.
Frame type¹	Specifies the frame type based on detection. This value is used for network adapters that support multiple frame types. The possible values are: Auto-detect (recommended) Ethernet 802.2 (default for NetWare 3.12 and later) Ethernet 802.3 Ethernet II Token-ring Token-ring Subnetwork Access Protocol (SNAP)
Maximum connections	Specifies the maximum number of connections that IPX will allow. Configured dynamically.
Maximum sockets	Specifies the maximum number of IPX sockets that IPX assigns. Configured dynamically.
Network address	Specifies the IPX network address as a four-byte value. Configured dynamically.
Source routing²	Specifies the cache size to use with source routing. This parameter is used only on token-ring networks, where it is used to turn on source routing. Important Cache size is specified by entry count, not byte count. The recommended value of 16 entries is the most efficient and best setting for most installations.

¹ Each time the computer starts, Windows 98 detects the frame type by sending a general RIP request in each frame format. Based on the responses received from routers, Windows 98 determines the most prevalent frame type used and sets that as the default frame type. ² Source routing is a method of routing data across bridges. For NetWare networks, this means forwarding NetWare frames across an IBM token-ring bridge. With NDIS protocols, source routing is done by the protocol. With ODI-based protocols, source routing is configured with the network adapter driver or using the NetWare route.com utility.

You should not need to change bindings in most circumstances. However, you can disable the bindings for a protocol if you do not want other computers using that protocol to see this computer. At least one protocol, however, must be bound to the network client for the computer to communicate with the network.

To change bindings for the IPX/SPX-compatible protocol

In Control Panel, double-click Network.
Double-click the instance of IPX/SPX-compatible Protocol that is bound to your network adapter.
Note
If the computer has multiple network adapters, the list will contain an instance of the IPX/SPX-compatible protocol for each network adapter. You must configure each adapter with its own settings. You can only have four instances of IPX/SPX on your system, so if you have more than four adapters are installed, you should bind IPX/SPX only to the adapters that will use this protocol.
Click the Bindings tab.
Click any network component to change its bindings.
If the option is checked, it is bound to the protocol. If it is not checked, that network component is not using the IPX/SPX-compatible protocol. For more information, see "Configuring Network Adapters" earlier in this chapter.
Note
Microsoft Client for NetWare Networks is always bound only to the IPX/SPX-compatible protocol. This network client cannot use another protocol.

Using NetBIOS over IPX

NetBIOS is an interface used by network applications to communicate with other NetBIOS-compliant applications. The NetBIOS interface is responsible for the following:

Establishing logical names on the network.
Establishing connections (called sessions) between two computers by use of their logical names on the network.
Transmitting data between networked computers.

Windows 98 provides a 32-bit, protected-mode driver to support NetBIOS services over IPX (Vnetbios.386). This implementation is compatible with the Novell NetBIOS support driver. Performance enhancements include acknowledgment of previous frames in response frames (called PiggyBackAck), plus a "sliding window" acknowledgment mechanism.

These NetBIOS enhancements are used only when the computer is communicating with other computers using IPX over NetBIOS, such as other computers running Windows 98, Windows NT, or NetWare when running Lotus Notes or other NetBIOS applications. NetBIOS over IPX is not necessary for computers running Windows 98 to be able to communicate with each other. The redirector and server networking components in Windows 98 communicate with the IPX protocol directly without NetBIOS.

Novell provides a terminate-and-stay resident (TSR) NetBIOS driver named Netbios.exe, which is a Level 1 NetBIOS provider that consumes about 40K of conventional memory. This driver acknowledges each frame received, thus increasing the amount of traffic generated when NetBIOS is used. With the Microsoft implementation of NetBIOS over IPX, you can remove the real-mode Netbios.exe TSR.

Note

A Windows 98 computer that uses IPX without NetBIOS can connect to a Windows NT 3.5 or later server that uses IPX without NetBIOS. However, the Windows NT 3.5 or later computer service can only connect to a Windows 98 computer running File and Printer Sharing for Microsoft Networks when the Windows 98 computer is using NetBIOS over IPX.

To use the IPX/SPX-compatible protocol with NetBIOS on a computer

In Control Panel, double-click Network.
Double-click the instance of IPX/SPX-compatible Protocol that is bound to your network adapter.
Note
If the computer has multiple network adapters, the list will contain an instance of the IPX/SPX-compatible protocol for each network adapter. You must configure each adapter with its own settings. You can only have four instances of IPX/SPX on your system, so if you have more than four adapters are installed, you should bind IPX/SPX only to the adapters that will use this protocol.
Click the Bindings tab.
Click the NetBIOS tab, and then click I want to enable NetBIOS Over IPX/SPX.

Technical Notes on IPX/SPX on NetWare Networks

There is no need to enable source routing on token-ring networks if the communication is on the same ring, even if one computer has it enabled.
SPX-II is a protocol definition for windowing and transmitting large packets over SPX. The IPX/SPX-compatible protocol included with Windows 98 (Nwlink.vxd) does not support SPX-II. Some third-party dynamic-link libraries (DLLs) provide SPX-II support when you are using Nwlink.vxd. However, if you are using a third-party DLL that provides SPX-II support and a program communicates directly with Nwlink.vxd, SPX-II support will not be available for that program.
When you install Windows 98 with the IPX/SPX-compatible protocol, parameters in Net.cfg and Shell.cfg will be moved to the registry if they are not already there. (If you are upgrading over an installation of Windows 95 that included the IPX/SPX-compatible protocol, those parameters will already have been moved to the registry.)
To determine the network address in IPX packets, Windows 98 checks the wire for RIP packets and chooses the most likely address. The network address is dynamic and changes when a new network address becomes more prevalent.
All transport layer interface (TLI) libraries can run on the IPX/SPX-compatible protocol in Windows 98. TLI is similar to TDI in Microsoft networking as a layer between the protocol and network adapter driver; this implementation is similar to STREAMS and provides a STREAMS environment for NetWare, but Windows 98 uses Windows Sockets instead.