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];   /* DLCIs ever seen */
		u_char	up[NGM_LMI_STAT_ARYSIZE];     /* DLCIs currently 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
								 November 13, 2012							       BSD