NAME    [Toc]    [Back]

     ng_lmi -- frame relay LMI protocol netgraph node type

SYNOPSIS    [Toc]    [Back]

     #include <netgraph/ng_lmi.h>

DESCRIPTION    [Toc]    [Back]

     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 channel. This node
     also supports the NGM_TEXT_STATUS control message.

HOOKS    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
     when all hooks have been disconnected.

SEE ALSO    [Toc]    [Back]

     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    [Toc]    [Back]

     The ng_lmi node type was implemented in FreeBSD 4.0.

AUTHORS    [Toc]    [Back]

     Julian Elischer <[email protected]>


FreeBSD 5.2.1		       January 19, 1999 		 FreeBSD 5.2.1