DLC_START_LS

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

The ioctl subroutine argument structure for starting a link station (dlc_sls_arg) has the following specifics:

The following common link station (LS) flags are not supported:

Item Description

STAT Specifies a station type for SDLC.

NEGO Specifies a negotiable station type for SDLC.
The raddr_name (remote address and name) field is only used for outgoing calls when the DLC_SLS_LSVC common LS flag is active.
The maxif (maximum I-field length) field can be set to any value greater than 0. See the DLCTOKEN Frame Encapsulation figure (Figure 1) for more details. DLCTOKEN adjusts this value to a maximum of 4060 bytes if set too large.
The rcv_wind (receive window) field can be set to any value between 1 and 127 inclusive. The recommended value is 127.
The xmit_wind (transmit window) field can be set to any value between 1 and 127 inclusive. The recommended value is 26.
The rsap (remote SAP) field can be set to any value except null SAP (0x00) or name-discovery SAP (0xFC). Also, the low-order bit must be set to 0 (B`nnnnnnn0') to indicate an individual address.
The max_repoll field can be set to any value from 1 to 255. The recommended value is 8.
The repoll_time field is defined in increments of 0.5 seconds and can be set to any value from 1 to 255, inclusive. The recommended value is 2, giving a time-out duration of 1 to 1.5 seconds.
The ack_time (acknowledgment time) field is defined in increments of 0.5 seconds, and can be set to any value between 1 and 255, inclusive. The recommended value is 1, giving a time-out duration of 0.5 to 1 second.
The inact_time (inactivity time) field is defined in increments of 1 second and can be set to any value between 1 and 255 inclusive. The recommended value is 48, giving a time-out duration of 48 to 48.5 seconds.
The force_time (force halt time) field is defined in increments of 1 second and can be set to any value between 1 and 16383, inclusive. The recommended value is 120, giving a time-out duration of approximately 2 minutes.

Item	Description
STAT	Specifies a station type for SDLC.
NEGO	Specifies a negotiable station type for SDLC.

A protocol-specific data area must be appended to the generic start link station argument (dlc_sls_arg). This structure provides DLCTOKEN with additional protocol-specific configuration parameters:


   struct trl_start_psd
{
   uchar_t    pkt_prty;   /* ring access packet priority   */
   uchar_t    dyna_wnd;   /* dynamic window increment      */
   ushort_t   reserved;   /* currently not used            */
};

The protocol-specific parameters are as follows:

Item	Description
`pkt_prty`	Specifies the ring access priority that the user wishes to reserve on transmit packets. Values of 0 to 3 are supported, where 0 is the lowest priority and 3 is the highest priority.
`dyna_wnd`	Specifies the number of consecutive sequenced packets that must be acknowledged by the remote station before the local transmit window count can be incremented. Network congestion causes the local transmit window count to drop automatically to a value of 1. The dynamic window increment allows a gradual increase in network traffic after a period of congestion. This field can be set to any value between 1 and 255, inclusive. The recommended value is 1.

Item

Description

pkt_prty

Specifies the ring access priority that the user wishes to reserve on transmit packets. Values of 0 to 3 are supported, where 0 is the lowest priority and 3 is the highest priority.

dyna_wnd

Specifies the number of consecutive sequenced packets that must be acknowledged by the remote station before the local transmit window count can be incremented. Network congestion causes the local transmit window count to drop automatically to a value of 1. The dynamic window increment allows a gradual increase in network traffic after a period of congestion. This field can be set to any value between 1 and 255, inclusive. The recommended value is 1.