No MSDLC Response to TEST Commands Received on Open SAPS

• Microsoft LAN Manager, versions 2.1a, 2.2, 2.2b

SYMPTOMS

According to the ISO specification for the 802.2 (DLC) protocol, MSDLC must respond with an LLC TEST response frame whenever it receives an LLC TEST command on any previously opened SAP. The MSDLC stack, however, responds only to TEST commands which it receives on SAP 0.

CAUSE

By default MS-DLC does not configure any intermediate transmit buffers, which are required from the transmission of TEST frames. Therefore, if MS-DLC receives any TEST frames on an open SAP it cannot respond due to a lack of buffers.

RESOLUTION

There is a hidden MS-DLC parameter, TRXBUFFERS, located in the MSDLC section of PROTOCOL.INI. By default TRXBUFFERS takes on the value 0 (zero). For the TEST frame response to work, you must set this parameter to 2.

MORE INFORMATION

Here is a complete list of the PROTOCOL.INI parameters for the MS-DOS MSDLC stack.

BINDINGS

List of MACs to bind to. MSDLC limits you to a maximum of 2 bindings.

COMMANDS

Number of CCB commands which can be pending in the stack at one time.

Range: 1 to 255. Default: 24.

IPACKETS

Number of session-packets (I-frames) which can be queued to transmit.

Range: 1 to 1000. Default: 24.

UIPACKETS

Number of non-session (UI-frames) which can be queued to transmit.

Range: 1 to 1000. Default: 16.

LOOPPACKETS

Range 1 to 1000 Default 2.

STACKSIZE

Size of MSDLC internal stack.

Range: 512 to 4096. Default: 2048.

DLCRETRIES

Times to retry packet trasmissions before disconnecting.

Range: 1 to 65535. Default: 8.

The following parameters control the dynamic windowing algorithm. See a description of these parameters for NetBEUI for an explanation.

ADAPTRATE

Milliseconds between runs of the adaptive window routines.

Range: 0 to 65535. Default: 0.

WINDOWERRORS

Range: 1 to 1000. Default: 10.

MAXIN

Range: 1 to 127. Default: 1.

MAXOUT

Range: 1 to 127. Default: 2.

The following parameters set the units used when specifing timer values in DLC.OPEN.SAP commands. These units are used as defaults, and may be overridden by parameters to the DIR.OPEN.ADAPTER command.

T1_TICK_ONE Retry Timeout

Range: 1 to 255. Default: 5.

T1_TICK_TWO

Range: 1 to 255. Default: 25.

T2_TICK_ONE Delayed Ack Timeout

Range: 1 to 255. Default: 1.

T2_TICK_TWO

Range: 1 to 255. Default: 10.

TI_TICK_ONE Inactivity timeout

Range: 1 to 255. Default: 25.

TI_TICK_TWO

Range: 1 to 255. Default: 125.

SAPS

Number of SAPS which may be opened simultaneously. See the IBM LAN Technical Reference for a description of SAPS

Range: 1 to 255. Default: 3

XSAPS0

Number of extra SAPS for adapter 0. If this is defined and is greater than the max SAP specified in the DIR.OPEN.ADAPTER command, then this value overrides the value suppled in DIR.OPEN.ADAPTER.

Range: 0 to 127. Default: 0.

XSAPS1

Number of extra SAPS for adapter 1. If this is defined and is greater than the max SAP specified in the DIR.OPEN.ADAPTER command, then this value overrides the value suppled in DIR.OPEN.ADAPTER.

Range: 0 to 127. Default: 0.

STATIONS

Number of Link Stations which may be opened simultaneously on all SAPS. This is not the same as the max stations which may opened on each SAP.

Range: 1 to 255. Default: 20.

XSTATIONS0

Number of extra STATIONS for adapter 0. If this is defined and is greater than the maximum STATION specified in the DIR.OPEN.ADAPTER command, then this value overrides the value suppled in DIR.OPEN.ADAPTER.

Range: 0 to 127. Default: 0.

XSTATIONS1

Number of extra STATIONS for adapter 1. If this is defined and is greater than the maximum STATION specified in the DIR.OPEN.ADAPTER command, then this value overrides the value suppled in DIR.OPEN.ADAPTER.

Range: 0 to 127. Default: 0.

DENYSAPS

Specifies a list of SAP values that may not be opened on the driver. This would be done if another APP were to be run on the same station which used a particular SAP value, to prevent a DLC APP from conflicting by opening the same SAP. A good example of this is a separate NetBIOS stack running, which would use SAP F0. The NetBIOS SAP (F0) is DENY'ed by default, but can be allowed by specifying a blank DENYSAPS line.

MAXGROUP

Maximum number of Group SAPs which may be opened simultaneously.

Range: 0 to 126. Default: 0.

MAXMEMBER

Maximum number of SAPs which can belong to each Group SAP.

Range: 0 to 127. Default: 0.

CLASS1TIMEOUT

Length of time in seconds a MAC should spend trying to send a UI frame before giving up and freeing the resources.

Range: 0 to 65. Default: 120.

BUFQELEMENTS

The total number of buffers which can be pooled in the driver at one time. This is not a per-pool limit, but a limit accross all pools.

Range: 1 to 2048. Default: 64.

TIMERS

Number of timers which can be running at one time using the DLC timer primitives.

Range: 1 to 255. Default: 12.

UNLOCKTIME

Number of seconds between lock thread wakeups

Range: 1 to 65. Default: 4.

USEDIX

For Ethernet only, this keyword selects the frame format. If it is set to zero, the driver uses 802.3 Ethernet format; if it is set to 1, the driver uses DIX (Ethertype 0x80D5) format.

Default: 802.3.

SWAP

If this value is 1, address bits are swapped.

Range: 0 to 1. Default: 1.

The driver has intermediate transmit buffers used to transmit frames with more then 8 source buffers chained, and controlled by these two parameters.

TRXBUFSIZE

Size in bytes of intermediate transmit buffers.

Range: 16 to 18000. Default: 16.

TRXBUFFERS

Number of intermediate transmit buffers. This must be set to 2 for TEST frames to work correctly.

Range: 0 to 32. Default: 0.

Additional query words: 2.20 3.1 3.11 2.1a 2.2b wfwg wfw

Keywords :
Version : :2.1a,2.2,2.2b
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