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
( annexAannexD
or
group4 )
to DLCI 0 or 1023 of a
ng_frame_relay4
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
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.