RFC2484 - PPP LCP Internationalization Configuration Option

领测软件测试网

　　 
　　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 Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

1. 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 RFC2277 [5].

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 [6].

3. 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

Description

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...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

28

Length

>= 7

MIBenum

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 RFC2278 [9].

The default charset value is UTF-8 [10]. The MIBenum value for
the UTF-8 charset is 106.

Language-Tag

The Language-Tag field is an ASCII string which contains a
language tag, as defined in RFC1766 [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].

4. 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)", RFC1994, August 1996.

[3] Simpson, W., "PPP LCP Extensions", RFC1570, January 1994.

[4] Blunk, L. and J. Vollbrecht, "PPP Extensible Authentication
Protocol (EAP)", RFC2284, March 1998.

[5] Alvestrand, H., "IETF Policy on Character Sets and Languages",
BCP 18, RFC2277, January 1998.

[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC2119, March 1997.

[7] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2, RFC1700,
October 1994. See also: http://www.iana.org/numbers.html

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

[9] Freed, N. and J. Postel, "IANA Charset Registration Procedures",
BCP 19, RFC2278, January 1998.

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

[11] Smith, R., Wright, F., Hastings, T., Zilles, S. and J.
Gyllenskog, "Printer MIB", RFC1759, March 1995.

5. 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.

6. Acknowledgements

Thanks to Craig Fox (fox@cisco.com), James Carlson
(carlson@ironbridgenetworks.com), Harald Alvestrand
(Harald.Alvestrand@maxware.no), Kevin Smith (kevin@ascend.com), Karl
Fox (karl@ascend.com), Thomas Narten (narten@raleigh.ibm.com) and
Narendra Gidwani (nareng@microsoft.com) for helpful suggestions and
feedback.

7. Chair's Address

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

Phone: +1 614 326 6841
EMail: karl@ascend.com

8. Author's Address

Glen Zorn
Microsoft Corporation
One Microsoft Way
Redmond, Washington 98052

Phone: +1 425 703 1559
Fax: +1 425 936 7329
EMail: glennz@microsoft.com

9. Full Copyright Statement

Copyright (C) The Internet Society (1999). All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

文章来源于领测软件测试网 https://www.ltesting.net/