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NG_RFC1490(4)		     Kernel Interfaces Manual		   NG_RFC1490(4)

NAME
     ng_rfc1490 -- RFC 1490 netgraph node type

SYNOPSIS
     #include <netgraph/ng_rfc1490.h>

DESCRIPTION
     The  rfc1490  node  type performs protocol encapsulation, de-encapsulation,
     and multiplexing according to RFC 1490 (which has since been updated by RFC
     2427).  This particular type of encapsulation is often used on top of frame
     relay DLCI channels.

     The downstream hook is used to transmit and  receive  encapsulated  frames.
     On  the other side of the node, the inet and ppp hooks are used to transmit
     and receive raw IP frames and PPP frames,	respectively.	PPP  frames  are
     transmitted  and  received according to RFC 1973; in particular, frames ap-
     pearing on the ppp hook begin with the PPP protocol number.   The	ethernet
     hook  can be used to transmit and receive Ethernet frames (without a check-
     sum) in RFC 1490's bridging format.

     Typically the inet hook is connected to the inet  hook  of  an  ng_iface(4)
     node.

HOOKS
     This node type supports the following hooks:

     downstream   Connects to the RFC 1490 peer entity.

     ethernet	  Transmits  and receives bridged raw Ethernet frames, without a
		  checksum.

     inet	  Transmits and receives raw IP frames.

     ppp	  Transmits and receives PPP frames.

CONTROL MESSAGES
     This node type supports the generic control messages, plus the following:

     NGM_RFC1490_SETENCAP
	     This command sets encapsulation method for the node.   The  desired
	     method must be passed as a string message argument, and must be one
	     of the following supported encapsulation modes:

	     "ietf-ip"	  IP packets are sent using simple RFC1490/2427 encapsu-
			  lation.

	     "ietf-snap"  IP packets are sent inside SNAP frames.  Also conforms
			  to RFC1490/2427.

	     "cisco"	  IP  packets  are  sent  and received using proprietary
			  Cisco encapsulation method.

     NGM_RFC1490_GETENCAP
	     This command returns current encapsulation method on the node.

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

BUGS
     Not all of RFC 1490 is implemented.

SEE ALSO
     netgraph(4), ng_frame_relay(4), ng_iface(4), ngctl(8)

     C.  Brown	and  A.  Malis, Multiprotocol Interconnect over Frame Relay, RFC
     2427.

     W. Simpson, PPP in Frame Relay, RFC 1973.

     http://www.cisco.com/warp/public/121/frf8modes.pdf

HISTORY
     The ng_rfc1490 node type was implemented in FreeBSD 4.0.

AUTHORS
     Julian Elischer <julian@FreeBSD.org>

FreeBSD 5.3			January 19, 1999		   NG_RFC1490(4)

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