CLNP(4) 						   BSD Kernel Interfaces Manual 						   CLNP(4)

NAME

     clnp -- Connectionless-Mode Network Protocol

SYNOPSIS

     #include <sys/socket.h>
     #include <netiso/iso.h>
     #include <netiso/clnp.h>

     int
     socket(AF_ISO, SOCK_RAW, 0);

DESCRIPTION

     CLNP is the connectionless-mode network protocol used by the connectionless-mode network service.	This protocol is specified in ISO 8473.
     It may be accessed through a ``raw socket'' for debugging purposes only.  CLNP sockets are connectionless, and are normally used with the
     sendto(2) and recvfrom(2) system calls, though the connect(2) call may also be used to fix the destination for future packets (in which case
     the read(2) or recv(2) and write(2) or send(2) system calls may be used).

     Outgoing packets automatically have a CLNP header prepended to them.  Incoming packets received by the user contain the full CLNP header.
     The following setsockopt(2) options apply to CLNP:

     CLNPOPT_FLAGS  Sets the flags which are passed to clnp when sending a datagram.  Valid flags are:

			  CLNP_NO_SEG	 Do not allow segmentation
			  CLNP_NO_ER	 Suppress ER pdus
			  CLNP_NO_CKSUM  Do not generate the CLNP checksum

     CLNPOPT_OPTS   Sets CLNP options.	The options must be formatted exactly as specified by ISO 8473, section 7.5 ``Options Part''.  Once an
		    option has been set, it will be sent on all packets until a different option is set.

CONGESTION EXPERIENCE BIT

     Whenever a packet is transmitted, the globally unique quality of service option is added to the packet.  The sequencing preferred bit and the
     low transit delay bit are set in this option.

     If a packet is forwarded containing the globally unique quality of service option, and the interface through which the packet will be trans-
     mitted has a queue length greater than congest_threshold, then the congestion experienced bit is set in the quality of service option.

     The threshold value stored in congest_threshold may be tuned.

     When a packet is received with the globally unique quality of service option present, and the congestion experienced bit is set, then the
     transport congestion control function is called.

DIAGNOSTICS

     A socket operation may fail with one of the following errors returned:

     [EISCONN]	      When trying to establish a connection on a socket which already has one, or when trying to send a datagram with the destina-
		      tion address specified and the socket is already connected;

     [ENOTCONN]       When trying to send a datagram, but no destination address is specified, and the socket hasn't been connected;

     [ENOBUFS]	      When the system runs out of memory for an internal data structure;

     [EADDRNOTAVAIL]  When an attempt is made to create a socket with a network address for which no network interface exists;

     [EHOSTUNREACH]   When trying to send a datagram, but no route to the destination address exists.

     [EINVAL]	      When specifying unsupported options.

SEE ALSO

     recv(2), send(2), intro(4), iso(4)

BUGS

     Packets are sent with the type code of 0x1d (technically an invalid packet type) for lack of a better way to identify raw CLNP packets.

     No more than MLEN bytes of options can be specified.

BSD
								   April 2, 1994							       BSD