From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc877.txt | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 doc/rfc/rfc877.txt (limited to 'doc/rfc/rfc877.txt') diff --git a/doc/rfc/rfc877.txt b/doc/rfc/rfc877.txt new file mode 100644 index 0000000..2350b76 --- /dev/null +++ b/doc/rfc/rfc877.txt @@ -0,0 +1,113 @@ +Network Working Group J. T. Korb +Request for Comments: 877 Purdue University + September 1983 + + + + A Standard for the Transmission of IP Datagrams + Over + Public Data Networks + + + + +This RFC specifies a standard adopted by CSNET, the VAN gateway, and +other organizations for the transmission of IP datagrams over the +X.25-based public data networks. + +An X.25 virtual circuit is opened on demand when a datagram arrives at +the network interface for transmission. A virtual circuit is closed +after some period of inactivity (the length of the period depends on +the cost associated with an open virtual circuit). A virtual circuit +may also be closed if the interface runs out of virtual circuits. An +algorithm for managing virtual circuits during peak demand is given +in [1]. + +STANDARDS + +1.1 The first octet in the Call User Data Field (the first data octet + in the Call Request packet) is used for protocol demultiplexing. + The value hex CC (binary 11001100, decimal 204) is used to mean + INTERNET PROTOCOL. + +1.2 IP datagrams are sent as X.25 "complete packet sequences". That is, + datagrams begin on packet boundaries and the M bit ("more data") is + used for datagrams that are larger than one packet. There are no + additional headers or other data in the packets. + +1.3 Unless a larger packet size is negotiated, the maximum size of an + IP datagram transmitted over X.25 is 576 octets. If two sites + negotiate a large X.25 packet size (for example, 1024 octets), an + IP datagram of that size is allowed. + +1.4 Either site may close a virtual circuit. If the virtual circuit is + closed or reset while a datagram is being transmitted, the datagram + is lost. + +GENERAL REMARKS + +2.1 Protocols above IP, such as TCP, do not affect this standard. In + particular, no attempt is made to open X.25 virtual circuits + corresponding to TCP connections. + + + + +Korb [Page 1] + +RFC 877 September 1983 +Transmission of IP Datagrams Over Public Data Networks + + +2.2 Features of X.25 not discussed in this document are not used. + For example, interrupt packets and the D bit (indicating + end-to-end significance) are not used. + +2.3 Negotiable features (facilities) of X.25 are allowed. For + example, sites are free to negotiate larger packet and window + sizes. + +2.4 Some sites, such as CSNET sites, may attempt to open multiple + virtual circuits to a single site. Sites should attempt to + handle such incoming calls gracefully: transmit on the + additional circuits if possible and accept incoming datagrams + from them, but do not accept the CALL REQUEST, only to + immediately close the connection or ignore datagrams + transmitted on such circuits. + + +REFERENCE + +[1] Comer, D.E. and Korb, J.T., "CSNET Protocol Software: The + IP-to-X.25 Interface", SIGCOMM Symposium on Communications + Architectures and Protocols, March 1983. + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Korb [Page 2] + -- cgit v1.2.3