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PPP LCP Internationalization Configuration Option

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 2484.
Author Glen Zorn
Last updated 2013-03-02 (Latest revision 1998-11-18)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Became RFC 2484 (Proposed Standard)
Consensus boilerplate Unknown
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Network Working Group                                            G. Zorn
Internet-Draft                                     Microsoft Corporation
Category: Standards Track                                  Novenber 1998
Updates: RFC 1570, RFC 1994, RFC 2284

           PPP LCP Internationalization Configuration Option

1.  Status of this Memo

This document is an Internet-Draft.  Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups.  Note that other groups may also distribute working
documents as Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time.  It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as ``work in progress''.

To learn the current status of any Internet-Draft, please check the
``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
Directories on (US East Coast), (Europe), (US West Coast), or (Pacific Rim).

The distribution of this memo is unlimited.  It is filed as <draft-ietf-
pppext-lcp-charset-07.txt> and expires May 20, 1999.  Please send
comments to the PPP Extensions Working Group mailing list (ietf- or to the author (

2.  Abstract

The Point-to-Point Protocol (PPP) [1] 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 [5].

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INTERNET-DRAFT       LCP Internationalization Option      November 1998

3.  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 [6].

4.  Additional LCP Configuration Option

The Configuration Option format and basic options are already defined
for LCP [1].

Up-to-date values of the LCP Option Type field are specified in STD 2
[7].  This document concerns the following value:

   28  Internationalization

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.

4.1.  Internationalization


      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...

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INTERNET-DRAFT       LCP Internationalization Option      November 1998




      >= 7


      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 [7].

      The charset registration procedure is described in RFC 2278 [9].

      The default charset value is UTF-8 [10].  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 [8].

      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" [8].

5.  References

[1]  Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661,
     July 1994

[2]  Simpson, W., "PPP Challenge Handshake Authentication Protocol
     (CHAP)", RFC 1994, August 1996

[3]  Simpson, W., "PPP LCP Extensions", RFC 1570, January 1994

[4]  Blunk, L. and Vollbrecht, J., "PPP Extensible Authentication Proto-
     col (EAP)", RFC 2284, March 1998

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[5]  Alvestrand, H., "IETF Policy on Character Sets and Languages", BCP
     18, RFC 2277, January 1998

[6]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
     Levels", BCP 14, RFC 2119, March 1997

[7]  Reynolds, J. and Postel, J., "Assigned Numbers", STD 2, RFC 1700,
     October 1994

[8]  Alvestrand, H., "Tags for the Identification of Languages", RFC
     1766, March 1995

[9]  Freed, N. and Postel, J., "IANA Charset Registration Procedures",
     BCP 19, RFC 2278, January 1998

[10] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC
     2279, January 1998

[11] Smith, R., et al., "Printer MIB", RFC 1759, March 1995

6.  Security Considerations

It is possible that an attacker might manipulate the option in such a
way that displayable messages would be unintelligible to the reader.

7.  Acknowledgements

Thanks to Craig Fox (, James Carlson
(, Harald Alvestrand
(, Kevin Smith (, Karl Fox
(, Thomas Narten ( and Narendra
Gidwani ( for helpful suggestions and feedback.

8.  Chair's Address

The PPP Extensions Working Group can be contacted via the current chair:

   Karl Fox
   Ascend Communications
   3518 Riverside Drive
   Suite 101
   Columbus, OH 43221

   Phone: +1 614 326 6841

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INTERNET-DRAFT       LCP Internationalization Option      November 1998

9.  Author's Address

Questions about this memo can also be directed to:

   Glen Zorn
   Microsoft Corporation
   One Microsoft Way
   Redmond, Washington 98052

   Phone: +1 425 703 1559
   FAX:   +1 425 936 7329

10.  Expiration Date

This memo is filed as <draft-ietf-pppext-lcp-charset-07.txt> and expires
on May 20, 1999.

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