NG_LMI(4) BSD Kernel Interfaces Manual NG_LMI(4)
NAME
ng_lmi -- frame relay LMI protocol netgraph node type
SYNOPSIS
#include <sys/types.h>
#include <netgraph/ng_lmi.h>
DESCRIPTION
The lmi node type performs the frame relay LMI protocol. It supports the ITU Annex A, ANSI Annex D, and Group-of-four LMI types. It also
supports auto-detection of the LMI type.
To enable a specific LMI type, connect the corresponding hook (annexA, annexD, or group4) to DLCI 0 or 1023 of a ng_frame_relay(4) node.
Typically, Annex A and Annex D live on DLCI 0 while Group-of-four lives on DLCI 1023.
To enable LMI type auto-detection, connect the auto0 hook to DLCI 0 and the auto1023 hook to DLCI 1023. The node will attempt to automati-
cally determine which LMI type is running at the switch, and go into that mode.
Only one fixed LMI type, or auto-detection, can be active at any given time.
The NGM_LMI_GET_STATUS control message can be used at any time to query the current status of the LMI protocol and each DLCI channel. This
node also supports the NGM_TEXT_STATUS control message.
HOOKS
This node type supports the following hooks:
annexA ITU Annex A LMI hook.
annexD ANSI Annex D LMI hook.
group4 Group-of-four LMI hook.
auto0 Auto-detection hook for DLCI 0.
auto1023 Auto-detection hook for DLCI 1023.
CONTROL MESSAGES
This node type supports the generic control messages, plus the following:
NGM_LMI_GET_STATUS
This command returns status information in a struct nglmistat:
#define NGM_LMI_STAT_ARYSIZE (1024/8)
struct nglmistat {
u_char proto[12]; /* Active proto (same as hook name) */
u_char hook[12]; /* Active hook */
u_char fixed; /* If set to fixed LMI mode */
u_char autod; /* If currently auto-detecting */
u_char seen[NGM_LMI_STAT_ARYSIZE]; /* bitmap DLCIs seen */
u_char up[NGM_LMI_STAT_ARYSIZE]; /* bitmap DLCIs up */
};
NGM_TEXT_STATUS
This generic message returns is a human-readable version of the node status.
SHUTDOWN
This node shuts down upon receipt of a NGM_SHUTDOWN control message, or when all hooks have been disconnected.
SEE ALSO
netgraph(4), ng_frame_relay(4), ngctl(8)
ANSI T1.617-1991 Annex D.
ITU-T Q.933 Digital Subscriber Signaling System No. 1 - Signaling Specification for Frame Mode Basic Call Control, Annex A.
HISTORY
The ng_lmi node type was implemented in FreeBSD 4.0.
AUTHORS
Julian Elischer <julian@FreeBSD.org>
BSD January 19, 1999 BSD
