ng_frame_relay
—
frame relay netgraph node type
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.
The ng_frame_relay
node type was implemented in
FreeBSD 4.0.
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.