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

automatically
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 chan

nel. 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-de

tecting */
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 ver

sion 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