Network Working Group G. Zorn
Request for Comments: 2484 Microsoft Corporation
Category: Standards Track January 1999
Updates: 2284, 1994, 1570
PPP LCP Internationalization Configuration Option
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (1999). All Rights Reserved.
The Point-to-Point Protocol (PPP)  provides a standard method for
transporting multi-protocol datagrams over point-to-point links. PPP
also defines an extensible Link Control Protocol (LCP), which allows
negotiation of an Authentication Protocol for authenticating its peer
before allowing Network Layer protocols to transmit over the link.
Both LCP and Authentication Protocol packets may contain text which
is intended to be human-readable [2,3,4]. This document defines an
LCP configuration option for the negotiation of character set and
language usage, as required by RFC 2277 .
2. Specification of Requirements
In this document, the key words "MAY", "MUST, "MUST NOT", "optional",
"recommended", "SHOULD", and "SHOULD NOT" are to be interpreted as
described in .
3. Additional LCP Configuration Option
The Configuration Option format and basic options are already defined
for LCP .
Zorn Standards Track [Page 1]RFC 2484 LCP Internationalization Option January 1999
Up-to-date values of the LCP Option Type field are specified in STD 2
. This document concerns the following value:
The Internationalization option described here MAY be negotiated
independently in each direction.
Only one instance of this option SHOULD be sent by an implementation,
representing its preferred language and charset.
If Internationalization option is rejected by the peer, the default
language and charset MUST be used to construct all human-readable
messages sent to the peer.
This Configuration Option provides a method for an implementation
to indicate to the peer both the language in which human-readable
messages it sends should be composed and the charset in which that
language should be represented.
A summary of the Internationalization option format is shown below.
The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
| Type | Length | MIBenum
MIBenum (cont) | Language-Tag...
Zorn Standards Track [Page 2]RFC 2484 LCP Internationalization Option January 1999
The MIBenum field is four octets in length. It contains a unique
integer value identifying a charset [5,11].
This value MUST represent one of the set of charsets listed in the
IANA charset registry .
The charset registration procedure is described in RFC 2278 .
The default charset value is UTF-8 . The MIBenum value for
the UTF-8 charset is 106.
The Language-Tag field is an ASCII string which contains a
language tag, as defined in RFC 1766 .
Language tags are in principle case-insensitive; however, since
the capitalization of a tag does not carry any meaning,
implementations SHOULD send only lower-case Tag fields.
The default Tag value is "i-default" .
 Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, RFC
1661, July 1994.
 Simpson, W., "PPP Challenge Handshake Authentication Protocol
(CHAP)", RFC 1994, August 1996.
 Simpson, W., "PPP LCP Extensions", RFC 1570, January 1994.
 Blunk, L. and J. Vollbrecht, "PPP Extensible Authentication