Organization: China Interactive Publishing Network (http://www.china-pub.com/)
RFC Document Chinese Translation Program (http://www.china-pub.com/compters/emook/aboutemook.htm)
E-mail: Ouyang@china-pub.com
Translator: 15222775 @ 61. (15222775 @ 61. Hbzzx2001@yahoo.com.cn)
Translation time: 2001-10-20
Copyright: This Chinese translation copyright belongs to China Interactive Publishing Network. Can be used for non-commercial use free reprint, but must
Keep the translation and copyright information of this document.
Network Working Group J. T. KORB
Request for Comments: 877 purdue university
September 1983
IP datagram transfer standard on public data online
(RFC877 - A Standard for the Transmission of IP DataGrams
Over public data networks
This RFC specifies the CSNET (VAN gateway) and other organizations that are based on X.25-based public data online.
IP Data Reporting Standards.
When the data is reported to the network interface, the X.25 virtual circuit is opened in accordance with the requirements for transmission. The virtual circuit is in several ways
The cycle (the length of the cycle depends on the overhead associated with the open virtual circuit); when the interface is exhausted, one
The virtual circuit may also be closed. The virtual circuit management algorithm in the peak demand period is given in [1].
standard
1.1
The first byte in the call user data field (the first data byte in the call request package) is used to protocol multiplexer.
The hexadecimal number CC (binary 11001100, decimal 204) is used to schedule IP protocols.
1.2
IP Data is sent as an X.25 "full package sequence". That is, the datagram begins with the packet boundary, then M bits "more data"
Details used to longer than one package. There is no additional head and other data in the package.
1.3
Unless larger package size has been negotiated, the maximum size of the IP datagram transmitted through X.25 is 576 bytes. in case
The two parties have negotiated a larger package size (eg, 1024 bytes), then this size IP package is allowed.
1.4
Essewhere can close the virtual circuit. If the duplicate circuit is turned off or reset when it is transferring, it will discard
This datagon is reported.
General comment
2.1
The protocol above IP, such as IP, etc., does not affect this standard. In detail, there is no establishment by opening the virtual circuit to respond to TCP.
Attempt to pick up.
2.2
The characteristics of X.25 not discussed in this document are not available. Such as interrupt packages and D bits (indicating that the side of the end is not available)
2.3
X.25 allows for negotiation. For example, the parties can freely negotiate larger packages and window sizes.
2.4
Some sites such as CSNet, etc., may try to open multiple virtual circuits arriving at the same site. Each site should try gentle
These input calls: If possible, transmit and receive input datagrams on the additional circuit, but cannot accept
Call request, but immediately close the connection or discard the packet transmitted on these circuits.
bibliography
[1] COMER, D.E. and KORB, J.T., "CSNet Protocol
Software: the
IP-TO-X.25 Interface ", Sigcomm Symposium on ON
Communications
Architectures and protocolls, march 1983.rfc877 - a standard for the transmission of ip DataGrams over public data networks
IP datagram transfer standard on public data online
1
RFC Document Translation Plan
