RFC 1151 (rfc1151) - Page 2 of 4
Version 2 of the Reliable Data Protocol (RDP)
Alternative Format: Original Text Document
RFC 1151 RDP - Version 2 April 1990
The 8-bit port size is probably too small to support a large range of
applications. Accordingly, the port size is now 16-bits. Port
numbers less than 1024 are reserved for well-defined applications.
Allocable ports begin at port number 1024.
Finally, because the checksum and port size have been changed, the
version number has been increased to 2.
0 0 0 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+---+---------------+
|S|A|E|R|N| |Ver| Header |
0 |Y|C|A|S|U|0|No.| Length |
|N|K|K|T|L| | | |
+-+-+-+-+-+-+---+---------------+
1 | Source Port |
+---------------+---------------+
2 | Destination Port |
+---------------+---------------+
3 | Data Length |
+---------------+---------------+
4 | |
+--- Sequence Number ---+
5 | |
+---------------+---------------+
6 | |
+--- Acknowledgement Number ---+
7 | |
+---------------+---------------+
8 | Checksum |
+---------------+---------------+
9 | Variable Header Area |
. .
. .
| |
+---------------+---------------+
RDP Header Format
Figure 1
Minor Errors and Ambiguities
Some ambiguities and minor errors have been found in RFC-908. They
are corrected in this section.
The value of the state variable, SND.UNA is treated inconsistently in
the pseudo-code on pages 21-29. On page 12, SND.UNA is defined as
Partridge & Hinden
