SLI(2)

NAME
sli - SS7 Signalling Link Interface (SLI) for STREAMS

SYNOPSIS
#include <ss7/sli.h>
fdesc = open(const char *name, int flags);

DESCRIPTION
This is an implementation of the Signalling Link Interface described in the OpenSS7 Signalling Link Interface Specification and documented in ITU-T Recommendation Q.703. It provides the signalling link service. The SLI supports two styles of driver. When an SLI driver is opened, it's physical point of appearance may be specified or unspecified depending on the style of the driver.

Style 1
    Style 1 drivers have a Physical Point of Attachment (PPA) address which is bound to the opened stream at the time that the stream is opened. These drivers are typically allocated a major and minor device number and a per-device character special device file entry in the /dev directory.

Style 2
    Style 2 drivers do not have a Physical Point of Attachment (PPA) address bound at the time that the device is opened. These drivers are typically allocated a major and minor device number using the clone open and then are attached to a PPA using the SL_ATTACH_REQ command.

M_PROTO COMMANDS
The following protocol commands are supported by drivers which conform to the Signalling Link Interface:

SL_INFO_REQ, SL_INFO_ACK
    When the SLI user wishes to obtain information about the driver's implementation of the interface, it issues an SL_INFO_REQ command. In response, the Signalling Link Service (SLS) provider will respond with an SL_INFO_ACK message with the following information:

    typdef struct {
        sl_ulong    sl_primitive;
        sl_ulong    sl_state;
        sl_ulong    sl_max_sdu;
        sl_ulong    sl_min_sdu;
        sl_ulong    sl_addr_length;
        sl_ulong    sl_ppa_style;
        sl_ulong    sl_version;
    } sl_info_ack_t;

SL_ATTACH_REQ, SL_OK_ACK, SL_ERROR_ACK
    This command and response are used in directing the device to attached to the specified Physical Point of Attachment address (PPA). The precise format of the PPA is device-specific and is provided in the specific device sections, e.g. acb56(7). Typically the address has two components: a signalling data terminal (SDT) component and a signalling data link (sdl) component. The PPA is provided in the SL_ATTACH_REQ command as follows:

    typedef struct {
        sl_ulong    sl_primitive;
        sl_ulong    sl_ppa_addr;
    } sl_attach_req_t;

    If the attach is successful, the SLS provider responds with an SL_OK_ACK; otherwise, it responds with an SL_ERROR_ACK. In addition to the normal errors which may be contained in the SL_ERROR_ACK, the following additional error codes may be returned:

    SL_OUTSTATE
        The device is not in the SL_UNATTACHED state. The sl_state component of the SL_ERROR_ACK contains the actual state of the interface.

    SL_BADADDR
        The address was invalid.

    SL_BADADDRTYPE
        Invalid address type.

    SL_BADPPA
        Invalid PPA identifier.

    SL_PPAINUSE
        The PPA specified in the attach command is already in use by another signalling link. The SLS does not permit multiiple SLS users to open streams through the same PPA: only one stream per PPA is allowed.

SL_DETACH_REQ, SL_OK_ACK, SL_ERROR_ACK
    The detach request is sent as an M_PROTO or M_PCPROTO message by the SLS User when it wishes to detach a IStyle 2 driver stream from a particular PPA. The stream must already be disabled. If the detach is successful, the SLS Provider response with an SL_OK_ACK; otherwise, it responds with an SL_ERROR_ACK with one of the following error codes:

    SL_OUTSTATE
        The device is not in the SL_ATTACHED state. The sl_state component of the SL_ERROR_ACK contains the actual state of the interface.

SL_ENABLE_REQ, SL_ENABLE_CON

SL_DISABLE_REQ, SL_DISABLE_CON

COPYRIGHT NOTICE

Copyright © 1997-2000 Brian Bidulock. All Rights Reserved.
PUBLIC LICENSE This license is provided without fee, provided that the above copyright notice and this public license must be retained on all copies, extracts, compilations and derivative works. Use or distribution of this work in a manner that restricts its use except as provided here will render this license void. The author(s) hereby waive any and all other restrictions in respect of their copyright in this software and its associated documentation. The authors(s) of this software place in the public domain any novel methods or processes which are embodied in this software. The author(s) undertook to write it for the sake of the advancement of the Arts and Sciences, but it is provided as is, and the author(s) will not take any responsibility in it.