(C) Copyright 1995 SK-SysKonnect,
a business unit of Schneider & Koch & Co. Datensysteme GmbH.
All rights reserved.

===============================================================================

SMTDOCU.TXT


Readme-File for SK-NET FDDI Adapters /
Subject: Using the Advanced SMT Parameters


Version/ Date/ Author of this file: v1.03 / 01.FEB.95 / M. Althoff


CONTENTS
1       SMT PARAMETERS
2       SBA / ESS PARAMETERS
2.1      OVERVIEW
2.2      EXAMPLE OF CONFIGURATION IN STATIC MODE
2.3      PARAMETER DESCRIPTION
2.4      LAN SERVER ULTIMEDIA
2.5      PROBLEM DETERMINATION

===============================================================================


This is a description of the advanced parameters available for
SK-NET FDDI adapters.  These parameters give access to FDDI
Station Management (SMT):

        General SMT parameters,
        Synchronous Bandwith Allocator (SBA) parameters,
        End Station Support (ESS) for synchronous mode.

For more details about SMT, refer to
        SMT Rev. 7.3 ANSI Standard X3T9.5/93-085


(1) SMT PARAMETERS
==================


PmfPassWd

Description:    Password for PMF Set Request
Help:   This keyword defines the password that all remote PMF
        (Parameter Management Frame) requests must provide to change
        FDDI attributes within the adapter.
        The value for PmfPassWd is 8 ASCII characters long and not
        case sensitive since lower case letters will be converted to
        upper cases.
        Password protection can be disabled by setting this keyword
        to all zeros (default), or by not specifying a PmfPassWd.


UserData

Description:    SMT User Data
Help :  This keyword provides local write access to the User Data
        attribute, registered as fddiSMT 17 in the SMT Standard.
        The User Data must be an ASCII string for compliance
        with the FDDI SMT Standard. It can be 32 bytes long and can
        contain any user data, for example station name, location, etc.


LerCutOffA/B

Description:    SMT LER Cutoff Attribute Port A / B
Help:   This keyword provides local write access to the LER Cutoff
        attributes, registered as fddiPORT 58 in the SMT Standard.
        This attributes identifies the excessive Link Error Rate that
        removes Port A/B (or Port S).
        This keyword is specified as absolute value of the base 10
        logarithm of the LER Cutoff value.
        The valid range reaches from 1E-4 to 1E-15. If a value outside the
        limits is specified, the upper/lower limit will be taken.
        If no value is specified, the default value for LerCutOffA/LerCutOffB
        (1E-7) will be used.


LerAlarmA/B

Description:    SMT LER Alarm Attribute Port A / B
Help:   This keyword provides local write access to the LER
        Alarm attributes, registered as fddiPORT 59 in the SMT Standard.
        This attributes identifies the excessive Link Error Rate
        that signals an alarm at Port A/B (or Port S).
        This keywords are specified as absolute values of the base 10
        logarithm of the LER Alarm value.
        The value range is 1E-4 ... 1E-15 for both keywords.
        If a value outside the limits is specified, the
        upper/lower limit will be taken. If no value is specified,
        the default value for LerAlarmA/LerAlarmB (1E-8) will be used.


TMin

Description:    SMT T-Min Attribute
Help:   This keyword provides local write access to the 2's complement
        T-Min attribute, registered as fddiMAC 55 in the SMT Standard.
        TMin is the minimum allowed value of the
        Token Rotation Timer (TRT). It affects the interoperability
        of the station in the ring. If a TRT is negotiated during
        the claim process which is less than the station's TMin,
        the station is unable to operate on the ring.
        The value for TMin is specified in milliseconds.
        The value range is 5 ms ... 165 ms. If a value
        outside the limits is specified, the upper/lower
        limit will be taken. If no value is specified,
        the default value for TMin (5 ms) will be used.


TMax

Description:    SMT T-Max Attribute
Help:   This keyword provides local write access to the 2's complement
        T-Max attribute, registered as fddiMAC 53 in the SMT Standard.
        TMax is the maximum allowed value of the Token
        Rotation Timer. The value of TMax is used to recover the
        ring when a fault is suspected. The value is specified in milliseconds.
        The value range is 5 ms ... 165 ms. If a value outside the limits
        is specified, the upper/lower limit will be taken. If no
        value is specified, the default value for TMax (165 ms) will be used.


TReq

Description:    SMT T-Req Attribute
Help:   This keyword provides local write access to the 2's complement
        T-Req attribute, registered as fddiMAC 51 in the SMT Standard.
        TReq specifies the requested target rotation time (TTRT)
        for this station.
        The value for TReq is specified in milliseconds.
        The value range is  5 ms ... 165 ms. If a value outside the limits
        is specified, the upper/lower limit will be taken. If no value
        is specified, the default value for TReq (165 ms) will be used.

NOTE:   During the claim process the lowest time value for TTRT is
        selected, by using a distributed process that involves the
        MACs in every station on the ring.


TVX

Description:    SMT TVX Attribute
Help:   This keyword provides local write access to the TVX
        attribute, registered as fddiMAC 54 in the SMT Standard.
        This attribute provides local control of the recovery time
        from transient ring errors.
        The value for TVX is specified in microseconds.
        The value range is 2500 us ... 10000 us. If a value
        outside the limits is specified, the upper/lower
        limit will be taken. If no value is specified,
        the default value for TVX (2700 us) will be used.

NOTE:	Due to hardware limitations the upper value for the TVX
	attribute is restricted to 5200 us. It is recommended to
	specify a value below this limit.




(2) SBA / ESS PARAMETERS
=========================

        (2.1) OVERVIEW

This chapter contains information about the adapter parameters you must
modify to configure the synchronous services.  The parameters configure
the operation of ESS and SBA functions.  These functions are part
of the device driver and are installed with it.

For instructions on SBA and ESS parameter modification, refer to chapter
2.3 of this documentation file you used to configure your environment.
The following sections describe the function and the range of values for
each parameter.

NOTE:   If you use static mode and configure this workstation to
        use synchronous transmission, you must change the default value
        for the
        - SbaCommand,
        - SbaPayLoad and
        - SynchTxMode parameters.

        Although you can change default values of the other parameters.
        Only advanced users are recommended to do so. Otherwise, a
        system failure may result.

These 2 tables will give you a summary of parameters required to configure SBA
and ESS in STATIC mode and in DYNAMIC mode; they also list default values.


  *****************************************************************************
  *  S T A T I C                                                              *
  *****************************************************************************

  +--------------------------------+------------------------------------------+
  |                                |                                          |
  | S B A                          | E S S                                    |
  |                                |                                          |
  +--------------------------------+------------------------------------------+
  | Name          Default Value    | Name           Default Value             |
  +--------------------------------+------------------------------------------+
  | SbaCommand    STOP             | SbaPayLoad     0 ( User MUST change it   |
  |                                |                    to get bandwidth )    |
  +--------------------------------+------------------------------------------+
  | SbaAvailable  50               | SbaOverHead    50                        |
  |               Not Applicable if|                Not Applicable (N/A) if   |
  |               SbaCommand = STOP|                SbaPayLoad = 0            |
  +--------------------------------+------------------------------------------+
  |                                | MaxTNeg        25                        |
  |                                |                N/A if SbaPayLoad = 0     |
  +--------------------------------+------------------------------------------+
  |                                | MinSegmentSize 1                         |
  |                                |                N/A if SbaPayLoad = 0     |
  +--------------------------------+------------------------------------------+
  |                                | SbaCategory    0                         |
  |                                |                N/A if SbaPayLoad = 0     |
  +--------------------------------+------------------------------------------+
  |                                | SynchTxMode    SPLIT                     |
  |                                |                N/A if SbaPayLoad = 0     |
  +--------------------------------+------------------------------------------+




  *****************************************************************************
  *  D Y N A M I C                                                            *
  *****************************************************************************

  +--------------------------------+------------------------------------------+
  |                                |                                          |
  | S B A                          | E S S                                    |
  |                                |                                          |
  +--------------------------------+------------------------------------------+
  | Name          Default Value    | Name             Default Value           |
  +--------------------------------+----------------+-------------------------+
  | SbaCommand    STOP             | SbaPayLoad     | SbaPayLoad MUST be 0.   |
  +--------------------------------+----------------+                         |
  | SbaAvailable  50               | SbaOverHead    | Application will        |
  |               N/A if           |                |                         |
  |               SbaCommand = STOP|                | request all needed      |
  +--------------------------------+----------------+                         |
  |                                | MaxTNeg        | parameters to Network   |
  |                                |                |                         |
  +--------------------------------+----------------+ Allocator.              |
  |                                | MinSegmentSize |                         |
  |                                |                |                         |
  +--------------------------------+----------------+                         |
  |                                | SbaCategory    |                         |
  |                                |                |                         |
  +--------------------------------+----------------+-------------------------+
  |                                | SynchTxMode    SPLIT                     |
  +--------------------------------+------------------------------------------+



        (2.2) EXAMPLE OF CONFIGURATION IN STATIC MODE

For example, a server S1 has 6 clients C1...C6 with ActionMedia cards
supporting videostreams of 1.2 Mbps each.
This means that the server has to support a payload of
        6 x 1.2 Mbps = 7.2 Mbps
This is equivalent to 112.5 Synchronous Units (see conversion formula
hereunder). Setting SbaPayLoad to 120 ensures sufficient server bandwidth
to guarantee quality of service for all videostreams.

Each client needs overall 2 Synchronous Units to send synchronous
request frames to the server.

NOTE:   If there is synchronous traffic on the FDDI ring, the fairness
        of the FDDI's asynchronous media access control is disturbed.
        This means the asynchronous stations in the ring have to delay
        their transmit requests.
        Therefore, it is necessary supply also the clients with some synchronous
        bandwidth to guarantee the synchronous data transfer within a
        stable time slot. The time slot value is 2 * TNeg.


                            +-------+  SbaPayLoad = 120 SbaOverHead    =    50
                            |  S 1  |                   MaxTNeg        =    25
                            | E S S |                   MinSegmentSize =   500
                            +-------+                   SbaCategory    =     0
                                |                       SynchTxMode    = SPLIT
                                |
                                |
             *****************************************
             *                                       *   +-------+
             *       F D D I     S E G M E N T       *---| S B A |
             *                                       *   +-------+
             *****************************************   SbaCommand   = START
                  |     |     |     |     |     |        SbaAvailable =    50
                  |     |     |     |     |     |
                +---+ +---+ +---+ +---+ +---+ +---+
                |C 1| |C 2| |C 3| |C 4| |C 5| |C 6|   For each client:
                +---+ +---+ +---+ +---+ +---+ +---+   SbaPayLoad     = 2
                                                      SbaOverHead    = 50
                                                      MaxTNeg        = 25
                                                      SynchTxMode    = SPLIT



        (2.3) PARAMETER DESCRIPTION


SbaCommand

Description:    SBA Command
Help:   This keyword is an SBA local action to start or stop the SBA
        application. The default value is 'STOP'.

NOTE:   There should be only one active SBA application in the same segment.


SbaAvailable

Description:    SbaAvailable Attribute
Help:   This keyword defines the maximum synchronous bandwidth in
        percent available for the primary path. The value range is
        0...100 percent. The default value is 50 percent (6.25 MBytes/s).
        If a value outside the limits is specified, the
        upper/lower limit will be taken. This value remains zero until
        the SBA application is enabled and active.


SbaPayLoad

Description:    SbaPayLoad Attribute
Help:   The SbaPayLoad keyword defines the requested synchronous
        bandwidth for manual static allocations in synchronous units (SU).
        The synchronous unit is the number of bytes transmitted in 125
        microseconds.

        Value range: 0 ... 1562 bytes per 125 microseconds.
        (1562 SU = 100 Mbits/sec).

        The correlation between a payload given in Mbits/sec and in Synchronous
        Units, as specified in the SMT ANSI Standard, is shown in the
        following table.

  +---------------------------------------------------------------------------+
  | Mbits/sec  1   2   3   4   5   10   15   20   25   30   35   40   45   50 |
  +---------------------------------------------------------------------------+
  | Payload   16  32  47  63  79  157  235  313  391  469  547  625  704  782 |
  +---------------------------------------------------------------------------+

        The default value is zero - no synchronous bandwidth is used.
        If a value outside the valid range is specified, the
        upper or lower limit will be taken.

        You must define the amount of bandwidth in order to send
        synchronous frames. If the SbaPayLoad keyword is not specified,
        the SbaOverHead, MaxTNeg, MinSegmentSize and SbaCategory keywords
        have no effects.

        The workstation supports either the static allocation mode (where
        the requested payload is specified by the SbaPayLoad keyword),
        or the dynamic allocation mode (where the required synchronous
        bandwidth is allocated directly by the multimedia application).

        If you use a multimedia application which can allocate
        the bandwidth dynamically, do not specify a value for
        the SbaPayLoad keyword.


        Conversion formula:

        (Requested Payload(Mbits/sec)  8)x 125E-6 = SbaPayLoad (SU)

        For example, if the required bandwidth is 1 MBit/sec
        (125,000 Bytes/sec), the value of the payload is
        125,000 x 125E-6 = 15.625 (rounded up to 16 SU).


SbaOverHead

Description:    SbaOverHead Attribute
Help:   This keyword defines the requested overhead for static
        allocations. The valid range reaches from 50 to 5000 bytes.
        If a value outside the limits is specified, the upper/lower
        limit will be taken. The default value is 50 bytes.

NOTE:   This keyword has only an effect, if the keyword SbaPayLoad is
        specified.


MaxTNeg

Description:    Maximum TNeg Attribute
Help:   This keyword defines the maximum token rotation delay which can
        be accepted by the application(s) using synchronous bandwidth.
        The value range is 5 ... 165 ms. If a value outside the limits is
        specified, the upper/lower limit will be taken.
        The default value is 25 ms.

NOTE:   This keyword has only an effect, if the keyword SbaPayLoad is
        specified.
CAUTION: If a value lower than 20 ms is specified for the MaxTNeg attribute,
        the SMT parameter TReq should be set to the same value
        (TReq = MaxTNeg). The synchronous payload request will be
        denied by the SBA if the value for the MaxTNeg parameter
        is lower than the current token rotation time.
        Refer to the description of the TReq parameter in chapter 2.


MinSegmentSize

Description:    Minimum Segmentation Size Attribute

Help:   This keyword defines the minimum synchronous segmentation size.
        This value corresponds to the amount of bytes to be transmitted
        per token opportunity. The value range is 1 ... 4478 bytes.
        If a value outside the limits is specified, the upper/lower limit will
        be taken. They default value is 1.

NOTE:   This keyword has only an effect, if the keyword SbaPayLoad is specified.


SbaCategory

Description:    SbaCategory Attribute
Help:   This keyword defines the session ID of the SBA_Category for the
        static allocation. The value range is 0 ...65535. If a value outside the
        limits is specified, the upper/lower limit will be taken.
        They default value is 0.

NOTE:   This keyword has only an effect, if the keyword SbaPayLoad is
        specified.


SynchTxMode

Description:    Synchronous Transfer Mode Attribute
Help:   The SynchTxMode keyword defines the synchronous transmission
        mode. The default value is 'SPLIT', where only frames identified
        as synchronous frames are transmitted by the synchronous queue.
        The alternative value is 'ALL', where all LLC frames received
        from upper layers are transmitted via the synchronous queue.
        This keyword only has an effect, if the ESS is able to allocate
        the required synchronous bandwidth from the SBA.


        (2.4) LAN SERVER ULTIMEDIA

If you are using LAN SERVER ULTIMEDIA V1.0 with LAN Server v3.0, you must
apply the APAR EC07262 providing a new NetBEUI driver for FDDI in
synchronous mode.


        (2.5) PROBLEM DETERMINATION

When problems according synchronous transmission arise, always ask your network
administrator for help.
The following questions can help to determine the failing part of the network.
These following questions assume that your adapter has been installed properly.


Q: Is there an SBA active on the segment ?

     A1: Check the SBACommand and verify that it is set to START.
         (default value : "STOP").
         Also check the SbaAvailable parameter (default is 50).
     A2: Check the fddiPATHSbaAvailable attribute (fddiPATH 20) with
         a network manager at the station where you started the SBA.
         If it is 0, the SBA is not started. Check the SbaCommand and
         SbaAvailable parameters and reboot the station.
     A3: Check if there is only one SBA instance on the segment. Multiple SBA
         on one segment may give you conflicts at workstation level between
         bandwidth allocation requests.


Q: Has the ESS received an answer from the SBA (request granted or denied) ?

     A: Check the fddiPATHSbaPayload attribute (fddiPATH 15) with a network
        manager on the station where you enabled the ESS.
        If it is 0, the SBA has denied the payload requested by the ESS.
        The ESS will keep requesting payload to the SBA every 10 seconds.


Q: Why did the SBA deny the allocation requests of my stations ESS ?

     A1: Check the SbaAvailable parameter and verify that the SBA
         has enough synchronous bandwidth to grant the allocation
         request of your station.
     A2: Check the fddiMACT-Neg attribute (fddiMAC 52) with a network
         manager on any station. If it exceeds the specified
         MaxTNeg parameter, set the your station's  SMT TReq attribute
         to the value of the MaxTNeg parameter. This problem can
         only occur, if MaxTNeg is lower than 20 ms.


Q: My ESS has had payload granted by the SBA. When I reboot it, is this
   payload still granted for this station or will the ESS send a new request ?

     A: Every time the ESS station boots, it sends an allocation request
        to the SBA, asking for payload according to the value specified
        in its PROTOCOL.INI file. The SBA grants or denies this request
        according to the bandwidth available. If the request is granted,
        the ESS is allowed to use this bandwidth.
        A communication protocol between the ESS and the SBA prevents
        the SBA from allocating payload more than once for an ESS.


Q: My ESS has had payload granted by the SBA and is now disconnected from
   the segment. What happens with the payload allocated for it ? Is it lost
   or could it be allocated for another station ?

     A: If ESS has been disconnected from the FDDI segment, SBA will detect
        it no longer than 8 minutes after ESS quits the segment. If this
        happens, the SBA is allowed to allocate this bandwidth to new
        requests.

***End of Readme File***