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AIXLink/X.25 1.1 for AIX: Guide and Reference

DL_INFO_ACK Primitive for X.25

Purpose

Returns information about the Data Link Provider Interface (DLPI) stream in response to the DL_INFO_REQ primitive.

Structure

This primitive consists of one M_PCPROTO message block with the following structure:

typedef struct {
   ulong dl_primitive;
   ulong dl_max_sdu;
   ulong dl_min_sdu;
   ulong dl_addr_length;
   ulong dl_mac_type;
   ulong dl_reserved;
   ulong dl_current_state;
   long dl_sap_length;
   ulong dl_service_mode;
   ulong dl_qos_length;
   ulong dl_qos_offset;
   ulong dl_qos_range_length;
   ulong dl_qos_range_offset;
   ulong dl_provider_style;
   ulong dl_addr_offset;
   ulong dl_version;
   ulong dl_brdcst_addr_length;
   ulong dl_brdcst_addr_offset;
   ulong dl_growth;
} dl_info_ack_t;

Description

The DL_INFO_ACK primitive returns information about the DLPI stream to the data link service (DLS). The DL_INFO_ACK primitive is a response to the DL_INFO_REQ primitive.

Parameters

dl_primitive Specifies the DL_INFO_ACK primitive.
dl_max_sdu Specifies the maximum number of bytes that can be transmitted in a data link service data unit (DLSDU). This value must be a positive integer greater than or equal to the value of the dl_min_sdu parameter.
dl_min_sdu Specifies the minimum number of bytes that can be transmitted in a DLSDU. The minimum value is 1.
dl_addr_length Specifies the length, in bytes, of the provider's data link service access point (DLSAP) address. For hierarchical subsequent binds, the length returned is the total length. The total length is the sum of the values for the physical address, service access point (SAP), and subsequent address length.
dl_mac_type Specifies the type of medium supported by this DLPI stream. This parameter can have the following value:
DL_HDLC Indicates the medium is a bit synchronous communication line.
dl_reserved Indicates a reserved field whose value must be set to 0.
dl_current_state    Specifies the state of the DLPI interface for the stream when the DLS provider issued this acknowledgment.
dl_sap_length Indicates the current length of the SAP component of the DLSAP address. The specified value must be an integer. The absolute value of the dl_sap_length parameter provides the length of the SAP component within the DLSAP address. The value can be one of the following:
>0 Indicates the SAP component precedes the PHYSICAL component within the DLSAP address.
<0 Indicates the PHYSICAL component precedes the SAP component within the DLSAP address.
0 Indicates that no SAP has been bound.
dl_service_mode If this DL_INFO_ACK primitive is returned before the DL_BIND_REQ primitive is processed, specifies the service mode the DLS provider can support. This parameter contains a bit-mask specifying the following value:
DL_CODLS Indicates connection-oriented data link service.

Once this service mode has been bound to the stream, this parameter returns that specific service mode.

dl_qos_length Specifies the length, in bytes, of the negotiated and selected values of the quality of service (QOS) parameters. The returned values are those agreed upon during negotiation.

If QOS has not yet been negotiated, default values are returned. These values correspond to those that are applied by the DLS provider on a connect request. For any parameter the DLS provider does not support or cannot determine, the corresponding entry will be set to DL_UNKNOWN. If the DLS provider does not support any QOS parameters, this length field is set to 0.

dl_qos_offset Specifies the offset from the beginning of the M_PCPROTO block to where the current QOS parameters begin.
dl_qos_range_length Specifies the length, in bytes, of the available range of QOS parameter values supported by the DLS provider. This range is available to the calling DLS user in a connect request.

For any parameter the DLS provider does not support or cannot determine, the corresponding entry is set to DL_UNKNOWN. If the DLS provider does not support any QOS parameters, this length field is set to 0.

dl_qos_range_offset Specifies the offset from the beginning of the M_PCPROTO block to where the available range of QOS parameters begin.
dl_provider_style Specifies the style of DLS provider associated with the DLPI stream. This parameter has the following value:
DL_STYLE1 Indicates the PPA is implicitly attached to the DLPI stream by opening the appropriate major or minor device number.
dl_addr_offset Specifies the offset of the address that is bound to the associated stream. If the DLS user issues a DL_INFO_REQ primitive before binding a DLSAP, the value of the dl_addr_length parameter is set to 0.
dl_version Indicates the version of the supported DLPI.
dl_brdcst_addr_length Indicates the length of the physical broadcast address.
dl_brdcst_addr_offset Indicates the offset of the physical broadcast address from the beginning of the PCPROTO block.
dl_growth Specifies a growth field for future use. The value of this parameter is 0.

States

Valid The message is valid in any state in response to a DL_INFO_REQ primitive.
New The resulting state is unchanged.

Implementation Specifics

This primitive is part of X.25 Licensed Program.

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