1 files changed, 73 insertions, 0 deletions
diff --git a/share/doc/smm/18.net/d.t b/share/doc/smm/18.net/d.t
new file mode 100644
index 0000000..675bece
--- /dev/null
+++ b/share/doc/smm/18.net/d.t
@@ -0,0 +1,73 @@
+.\" Copyright (c) 1983, 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)d.t	8.1 (Berkeley) 6/8/93
+.\"
+.nr H2 1
+.\".ds RH "Out of band data
+.br
+.ne 2i
+.NH
+\s+2Out of band data\s0
+.PP
+Out of band data is a facility peculiar to the stream socket
+abstraction defined.  Little agreement appears to exist as
+to what its semantics should be.  TCP defines the notion of
+``urgent data'' as in-line, while the NBS protocols [Burruss81]
+and numerous others provide a fully independent logical
+transmission channel along which out of band data is to be
+sent.
+In addition, the amount of the data which may be sent as an out
+of band message varies from protocol to protocol; everything
+from 1 bit to 16 bytes or more.
+.PP
+A stream socket's notion of out of band data has been defined
+as the lowest reasonable common denominator (at least reasonable
+in our minds);
+clearly this is subject to debate.  Out of band data is expected
+to be transmitted out of the normal sequencing and flow control
+constraints of the data stream.  A minimum of 1 byte of out of
+band data and one outstanding out of band message are expected to
+be supported by the protocol supporting a stream socket.
+It is a protocol's prerogative to support larger-sized messages, or
+more than one outstanding out of band message at a time.
+.PP
+Out of band data is maintained by the protocol and is usually not
+stored in the socket's receive queue.
+A socket-level option, SO_OOBINLINE,
+is provided to force out-of-band data to be placed in the normal
+receive queue when urgent data is received;
+this sometimes amelioriates problems due to loss of data
+when multiple out-of-band
+segments are received before the first has been passed to the user.
+The PRU_SENDOOB and PRU_RCVOOB
+requests to the \fIpr_usrreq\fP routine are used in sending and
+receiving data.