ng_frame_relay —
frame relay netgraph node type
#include
<netgraph/ng_frame_relay.h>
The
frame_relay node type performs encapsulation,
de-encapsulation, and multiplexing of packets using the frame relay protocol.
It supports up to 1024 DLCI's. The LMI protocol is handled by a separate node
type (see
ng_lmi(4)).
The
downstream hook should be connected to
the synchronous line, i.e., the switch. Then hooks
dlci0,
dlci1, through
dlci1023 are available to connect to each
of the DLCI channels.
This node type supports the following hooks:
- downstream
- The connection to the synchronous line.
- dlciX
- Here X is a decimal number from 0 to 1023. This hook
corresponds to the DLCI X frame relay virtual channel.
This node type supports only the generic control messages.
This node shuts down upon receipt of a
NGM_SHUTDOWN control message, or when all
hooks have been disconnected.
netgraph(4),
ng_lmi(4),
ngctl(8)
The
ng_frame_relay node type was implemented in
FreeBSD 4.0.
Julian Elischer
<
[email protected]>
Technically, frames on DLCI X should not be transmitted to the switch until the
LMI protocol entity on both ends has configured DLCI X as active. The
ng_frame_relay node type ignores this
restriction, and will always pass data received on a DLCI hook to
downstream. Instead, it should query the
LMI node first.