Multiprotocol Interconnect on X.25 and ISDN in the Packet Mode (RFC1356)
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
A. Malis: AUTHOR [+3]
This document specifies the encapsulation of IP and other network layer protocols over X.25 networks, in accordance and alignment with ISO/IEC and CCITT standards. It is a replacement for RFC 877, "A Standard for the Transmission of IP Datagrams Over Public Data Networks" .
Network Working Group A. Malis
Request for Comments: 1356 BBN Communications
Obsoletes: RFC 877 D. Robinson
Computervision Systems Integration
Process Software Corporation
on X.25 and ISDN in the Packet Mode
Status of this Memo
This RFC specifies an IAB standards track protocol for the Internet
community, and requests discussion and suggestions for improvements.
Please refer to the current edition of the "IAB Official Protocol
Standards" for the standardization state and status of this protocol.
Distribution of this memo is unlimited.
This document specifies the encapsulation of IP and other network
layer protocols over X.25 networks, in accordance and alignment with
ISO/IEC and CCITT standards. It is a replacement for RFC 877, "A
Standard for the Transmission of IP Datagrams Over Public Data
It was written to correct several ambiguities in the Internet
Standard for IP/X.25 (RFC 877), to align it with ISO/IEC standards
that have been written following RFC 877, to allow interoperable
multiprotocol operation between routers and bridges over X.25, and to
add some additional remarks based upon practical experience with the
specification over the 8 years since that RFC.
The substantive change to the IP encapsulation is an increase in the
allowed IP datagram Maximum Transmission Unit from 576 to 1600, to
reflect existing practice.
This document also specifies the Internet encapsulation for
protocols, including IP, on the packet mode of the ISDN. It applies
to the use of Internet protocols on the ISDN in the circuit mode only
when the circuit is established as an end-to-end X.25 connection.
RFC 877 was written by J. T. Korb of Purdue University, and this
document follows that RFC's format and builds upon its text as
appropriate. This document was produced under the auspices of the IP
over Large Public Data Networks Working Group of the IETF.
The following language conventions are used in the items of
specification in this document:
o MUST -- the item is an absolute requirement of the specification.
MUST is only used where it is actually required for interoperation,
not to try to impose a particular method on implementors where not
required for interoperability.
o SHOULD -- the item should be followed for all but exceptional
o MAY or optional -- the item is truly optional and may be followed
or ignored according to the needs of the implementor.
The words "should" and "may" are also used, in lower case, in thei...