DLC_ALTER

This section explains the ioctl subroutine argument structure for altering a link station.

The ioctl subroutine argument structure for altering a link station, dlc_alter_arg, has the following specifics:

• The following common alter flags are not supported:

  Item	Description
  SM1, SM2	Sets SDLC control mode.

• A protocol-specific data area must be appended to the generic alter link station argument structure (dlc_alter_arg). This structure provides DLC FDDI with additional protocol-specific alter parameters.

  
  #define FDL_ALTER_PRTY 0x80000000 /* alter packet priority   */
  #define FDL_ALTER_DYNA 0x40000000 /* alter dynamic window incr*/
  struct fdl_alter_psd
  {
  ulong_t        flags;     /* specific alter flags           */
  uchar_t        pkt_prty;  /* ring access packet priority value */
  uchar_t        dyna_wnd;  /* dynamic window increment value */
  ushort_t       reserved;  /* currently not used     */
  };
  

  
  #define FDL_ALTER_PRTY 0x80000000 /* alter packet priority   */
  #define FDL_ALTER_DYNA 0x40000000 /* alter dynamic window incr*/
  struct fdl_alter_psd
  {
  __ulong32_t    flags;     /* specific alter flags           */
  uchar_t        pkt_prty;  /* ring access packet priority value */
  uchar_t        dyna_wnd;  /* dynamic window increment value */
  ushort_t       reserved;  /* currently not used     */
  };
  

• Specific alter flags include:

  Item	Description
  FDL_ALTER_PRTY	Specifies alter priority. If set to 1, the pkt_prty value field replaces the current priority value being used by the link station. The link station must be started for this alter command to be valid.
  FDL_ALTER_DYNA	Specifies alter dynamic window. If set to 1, the dyna_wnd value field replaces the current dynamic window value being used by the link station. The link station must be started for this alter command to be valid.

  The protocol-specific parameters are:

  Item	Description
  pkt_prty	Specifies the new priority reservation value for transmit packets.
  dyna_wnd	Specifies the new dynamic window value to control network congestion.