NBF (NetBEUI) Transport Entries

The startup parameters for the NetBEUI (NBF) transport are found under the following subkey:


HKEY_LOCAL_MACHINE\SYSTEM\Services\NBF\Parameters

Note The parameters that control network bindings for this service are described in "NetRules Subkey Entries," earlier in this chapter. You should set the Export and Bind parameters by using the Network application in Control Panel.

The Initxxx entries for NBF define the initial allocation and the size of free memory for items. The Maxxxx entries define the upper limits. Within these ranges, the system autotunes performance. By default, the NBF service uses all the resources necessary to handle client requests, and when it is not actively working, it doesn't use many resources. Set Initxxx values to control initial allocation, which can make the system a little faster when you know a server will be busy. Set the Maxxxx values to control limits when you don't want the server to be too busy or to use too much memory for networking.

With Registry Editor, you can modify the following startup parameters for the NBF transport:

AddNameQueryRetries REG_DWORD Number

Specifies the number of times that NBF will retry sending ADD_NAME_QUERY and ADD_GROUP_NAME_QUERY frames. Adjust this parameter only if NBF is registering addresses on a network that drops many packets.

Default: 3

AddNameQueryTimeout REG_DWORD 100-nanosecond units

Specifies the time-out between NBF sending successive ADD_NAME_QUERY and ADD_GROUP_NAME_QUERY frames. Adjust this parameter only if NBF is registering addresses on a network with slow computers or over a slow network.

Default: 5000000

GeneralRetries REG_DWORD Number

Specifies the number of times that NBF will retry sending STATUS_QUERY and FIND_NAME frames. Adjust this parameter only if NBF is operating on a network that drops many packets.

Default: 3

DefaultT1Timeout REG_DWORD 100-nanosecond units

Specifies the initial value for the T1 timeout. T1 controls the time that NBF waits for a response after sending a logical link control (LLC) poll packet before resending it. Adjust this parameter only if NBF will be connecting over slow networks or to slow remote computers (although NBF does adapt).

Default: 6000000 (600 milliseconds)

DefaultT2Timeout REG_DWORD 100-nanosecond units

Specifies the initial value for the T2 timeout. T2 controls the time that NBF can wait after receiving an LLC poll packet before responding. It must be much less than T1; one-half or less is a good general rule. Adjust this parameter only if NBF will be connecting over slow networks or to slow remote computers.

Default: 1500000 (150 milliseconds)

DefaultTiTimeout REG_DWORD 100-nanosecond units

Specifies the initial value for the Ti timeout. Ti is the inactivity timer. When it expires, NBF sends an LLC poll packet to ensure that the link is still active. Adjust this parameter only if NBF is connecting over networks with unusual reliability characteristics, or over slow networks or to slow computers.

Default: 300000000 (30 seconds)

GeneralTimeout REG_DWORD 100-nanosecond units

Specifies the time-out between NBF sending successive STATUS_QUERY and FIND_NAME requests. Adjust this parameter only if NBF is operating on a network with slow computers or over a slow network.

Default: 5000000

InitAddresses REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial addresses to allocate within any memory limits that might imposed on NBF. Addresses correspond to NetBIOS names. An address is for the actual name, and an address file is for a TDI (Transport Driver Interface) client using that name; so usually you have the same number, but if two users open the same address, that is two address files but only one address.

Set this parameter if you know that a large number of addresses are needed. Otherwise, the system automatically allocates space for addresses as needed.

Default: 0 (no limit)

InitAddressFiles REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial address files to allocate within any memory limits that might imposed on NBF. Set this parameter if you know that a large number of address files are needed. Otherwise, the system automatically allocates space for address files as needed.

Default: 0 (no limit)

InitConnections REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial connections (NetBIOS sessions) to allocate within any memory limits that might imposed on NBF. Set this parameter if you know that a large number of connections are needed. Otherwise, the system automatically allocates space for connections as needed.

Default: 1

InitLinks REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial LLC links to allocate within any memory limits that might imposed on NBF. Typically, you have one connection per LLC link to another network adapter card, because the redirector puts all links to a computer into one connection. However, you may have more if two computers are communicating with each other or if a NetBIOS application is running. Set this parameter if you know that a large number of links are needed. Otherwise, the system automatically allocates space for links as needed.

Default: 2

InitReceiveBuffers REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial receive buffers to allocate. Receive buffers are used by NBF when it calls NDIS TransferData for received datagrams. Usually, this value is allocated as needed, but you can use this parameter to preallocate memory if you know a large number of datagram frames will be received.

Default: 5

InitReceivePackets REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial receive packets to allocate. Receive packets are used by NBF when it calls NDIS TransferData for received data. Usually, this value is allocated as needed, but you can use this parameter to preallocate memory if you know a large number of UI frames will be received.

Default: 10

InitRequests REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial requests to allocate within any memory limits that might imposed on NBF. Requests are used for in-progress connect requests, remote adapter status requests, find name requests, and so on. Set this parameter if you know that a large number of requests are needed. Otherwise, the system automatically allocates space for requests as needed.

Default: 5

InitSendPackets REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial send packets to allocate. Send packets are used by NBF whenever it sends connection-oriented data on behalf of a client. Usually, this value is allocated as needed, but you can use this parameter to preallocate memory if you know a large number of data frames are needed or if you see a lot of "send packets exhausted" messages when using Performance Monitor.

Default: 30

InitUIFrames REG_DWORD 1 or higher; 0 = no limit

Specifies the number of initial UI frames to allocate. UI frames are used by NBF to establish connections and for connectionless services such as datagrams. Usually, this value is allocated as needed, but you can use this parameter to preallocate memory if you know a large number of UI frames are needed.

Default: 5

LLCMaxWindowSize REG_DWORD Number of frames

Specifies the number of LLC I-frames that NBF can send before polling and waiting for a response from the remote. Adjust this parameter only if NBF is communicating over a network whose reliability often changes suddenly.

Default: 10

LLCRetries REG_DWORD 1 or higher; 0 = no limit

Specifies the number of times that NBF will retry polling a remote workstation after receiving a T1 timeout. After this many retries, NBF closes the link. Adjust this parameter only if NBF is connecting over networks with unusual reliability characteristics.

Default: 8

MaxAddresses REG_DWORD 1 or higher; 0 = no limit

Specifies the maximum number of addresses that NBF allocates within any memory limits that might imposed on NBF. Addresses are NetBIOS names that are registered on the network by NBF. An address is for the actual name, and an address file is for a TDI client using that name.

Use this optional parameter to fine-tune use of NBF memory. Typically this parameter is used to control address resources with an unlimited NBF.

Default: 0 (no limit)

MaxAddressFiles REG_DWORD 1 or higher; 0 = no limit

Specifies maximum number of address files that NBF allocates within any memory limits that might imposed on NBF. Each address file corresponds to a client opening an address.

Use this optional parameter to fine-tune use of NBF memory. Typically this parameter is used to control address files with an unlimited NBF.

Default: 0 (no limit)

MaxConnections REG_DWORD 1 or higher; 0 = no limit

Specifies the maximum number of connections that NBF allocates within any memory limits that might imposed on NBF. Connections are established between NBF clients and similar entities on remote computers.

Use this optional parameter to fine-tune use of NBF memory. Typically this parameter is used to control connection resources with an unlimited NBF.

Default: 0 (no limit)

MaximumIncomingFrames REG_DWORD 1 or higher; 0 = off

Used in some cases to control how many incoming frames NBF will receive before it sends an acknowledgment to a remote machine. In general, NBF automatically senses when to sends acknowledgments, however when communicating with some Microsoft LAN Manager or LAN Server remote computers configured with a very low value for maxout, this parameter can be set to an equal or lower value to improve network performance. (This parameter corresponds roughly to the Microsoft LAN Manager maxin parameter.) A value of 0 turns off this hint, causing NBF to revert to usual behavior. For communication with most all remotes, this parameter isn't used.

Default: 2

MaxLinks REG_DWORD 1 or higher; 0 = no limit

Specifies the maximum number of links that NBF allocates within any memory limits that might imposed on NBF. Links are established for every remote adapter to which NBF communicates.

Use this optional parameter to fine-tune use of NBF memory. Typically this parameter is used to control link resources with an unlimited NBF.

Default: 0 (no limit)

MaxRequests REG_DWORD 1 or higher; 0 = no limit

Specifies the maximum number of requests that NBF allocates within any memory limits that might imposed on NBF. Requests are used by NBF to control send, receive, connect, and listen operations.

Use this optional parameter to fine-tune use of NBF memory. Typically this parameter is used to control request resources with an unlimited NBF.

Default: 0 (no limit)

NameQueryRetries REG_DWORD Number

Specifies the number of times that NBF will retry sending NAME_QUERY frames. Adjust this parameter only if NBF is connecting to computers over a network that drops many packets.

Default: 3

NameQueryTimeout REG_DWORD 100-nanosecond units

Specifies the time-out between NBF sending successive NAME_QUERY frames. Adjust this parameter only if NBF is connecting to slow computers or over a slow network.

Default: 5000000

QueryWithoutSourceRouting REG_DWORD 0 or 1

When you are using NBF over a Token Ring driver, this parameter instructs NBF to send half the queries without including source routing information when connecting to a remote computer. This supports bridging hardware that cannot forward frames that contain source routing information.

Default: 0 (false)

UseDixOverEthernet REG_DWORD 0 or 1

Specifies whether NBF should use DIX encoding when bound to an Ethernet MAC. When using DIX encoding is enabled, NBF cannot talk to computers that use the standard IEEE 802.3 encoding.

Default: 0 (false)

WanNameQueryRetries REG_DWORD Number

Specifies the number of times that NBF will retry sending NAME_QUERY frames when connecting with RAS. Adjust this parameter only if NBF is connecting to computers over a network that drops many packets.

Default: 5