NetBEUI
NetBEUI |
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The following sections discuss problems that you might encounter on a Windows 2000–based computer on which the NetBEUI (or NetBIOS Frame) protocol is installed and running.
When NetBEUI is installed on a Windows 2000-based computer, because it is largely self-tuning, no configuration is required during installation.
If desired, however, you can change the default values for NetBEUI registry entries. The NetBEUI startup entries are found under the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\Services\NBF\Parameters
Warning
Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Microsoft Management Console (MMC) or Control Panel whenever possible.
You can make the following status changes to NetBEUI bindings:
To change a NetBEUI binding positions
Do not bind NetBEUI to multiple adapters on the same physical network or on bridged Ethernet segments. If NetBEUI is bound to multiple adapters on the same physical network or on bridged networks, each adapter attempts to register the same NetBIOS name on the network, causing a conflict to be generated. This might result in disabled adapters and any NetBEUI network connectivity to be lost.
Source routing is only supported for Token Ring networks. A network using a Fiber Data Distributed Interface (FDDI) for network communications cannot use NBF for source routing. To correct this problem, use transparent source routing or transparent bridging.
NBF does not use NetBIOS Session Alive frames to determine if the remote client is present; instead, it sends LLC poll frames, which perform the same function. NBF, however, responds to Session Alive frames, so no interoperability problems with other implementations of NetBEUI should be expected.
In general, NBF has no receive window, unless it detects that the remote sending computer is running a version of IBM NetBEUI that does not use network polling — for example, a computer running IBM LAN Server. NBF initiates a link with a remote computer in the same manner as IBM NetBEUI; however, NBF looks for a poll bit in received frames. If a frame is received that does not have the poll bit set, the Windows 2000–based computer waits until T2 expires before sending a frame ACK. For more information about T2, see "Connection-Oriented Network Communications" earlier in this chapter.
Note
When the poll bit is set in a received frame, NBF ignores the receive window and immediately sends an ACK.
For example, an IBM LAN Server computer is a nonpolling system that might have a send window set to 1. If this is the case, the registry parameter MaxIncomingFrames need to be decreased to 1 from its default of 2. If not, the non-Windows 2000–based computer waits for an ACK from the Windows 2000–based computer, which in this case is sent only when the T2 time limit expires.
NBF uses a receive window based on the value of MaximumIncomingFrames in the registry. The default value for MaximumIncomingFrames is 2, and this value does not dynamically change. The default value must be manually changed in the registry.
Note
When a Windows 2000–based computer is using the MaxIncomingFrames receive window, it might not always send an Acknowledgment frame after receiving MaxIncomingFrames packets. This is because NBF also waits until it receives an NDIS ProtocolReceiveComplete packet before sending the ACK. However, when the Windows 2000–based computer receives Poll frames, it sends the ACK immediately (typically on return from NdisTransferData [synchronous communications] or within ProtocolTransferDataComplete [asynchronous communications]).
Browsing (viewing other computers on the network) on a computer running Windows 2000 is done per protocol. In other words, there is a master browser for each protocol. Computers running only the NetBEUI protocol register with the master browser computer running the NetBEUI protocol. Computers running only NetBEUI get the master browser list from the master browser running NetBEUI. Because computers running only the TCP/IP protocol register with a master browser running TCP/IP, these computers are not on the master browser list of a computer running only NetBEUI. For information about browsing, see "Browser Service" in the TCP/IP Core Networking Guide.