HTTP/1.1 200 OK Date: Tue, 09 Apr 2002 06:36:59 GMT Server: Apache/1.3.20 (Unix) Last-Modified: Thu, 27 Mar 1997 18:45:00 GMT ETag: "361b1a-1aec-333ac02c" Accept-Ranges: bytes Content-Length: 6892 Connection: close Content-Type: text/plain Network Working Group W. Simpson, Editor Internet Draft DayDreamer expires in six months November 1996 PPP CallBack draft-ietf-pppext-callback-ds-00.txt Status of this Memo Distribution of this memo is unlimited. This document is an Internet-Draft. Internet Drafts are working doc- uments of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute work- ing 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 not appropriate to use Internet Drafts as refer- ence material, or to cite them other than as a ``working draft'' or ``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: ftp.is.co.za (Africa) nic.nordu.net (Europe) ds.internic.net (US East Coast) ftp.isi.edu (US West Coast) munnari.oz.au (Pacific Rim) Abstract The Point-to-Point Protocol (PPP) [1] provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP defines an extensible Link Control Protocol (LCP) for establishing, configuring, and testing the data-link connection. This document defines several additional LCP features that have been suggested over the past few years. Simpson expires in six months [Page i] DRAFT PPP CallBack November 1996 1. Additional LCP Configuration Options 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 the most recent "Assigned Numbers" [2]. This document concerns the fol- lowing values: 13 CallBack 1.1. CallBack Description This Configuration Option provides a method for an implementation to request a dial-up peer to call back. This option might be used for many diverse purposes, such as savings on toll charges. When CallBack is successfully negotiated, and authentication is complete, the Authentication phase proceeds directly to the Termi- nation phase, and the link is disconnected. Then, the peer re-establishes the link, without negotiating Call- Back. Implementation Notes: A peer which agrees to this option SHOULD request the Authenti- cation-Protocol Configuration Option. The user information learned during authentication can be used to determine the user location, or to limit a user to certain locations, or merely to determine whom to bill for the service. Authentication SHOULD be requested in turn by the implementa- tion when it is called back, if mutual authentication is desired. A summary of the CallBack Option format is shown below. The fields are transmitted from left to right. Simpson expires in six months [Page 1] DRAFT PPP CallBack November 1996 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 | Operation | Message ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 13 Length >= 3 Operation The Operation field is one octet and indicates the contents of the Message field. 0 location is determined by user authentication 1 Dialing string, the format and contents of which assumes configuration knowledge of the specific device which is making the callback. 2 Location identifier, which may or may not be human read- able, to be used together with the authentication informa- tion for a database lookup to determine the callback loca- tion. 3 E.164 number. 4 Distinguished name. Message The Message field is zero or more octets, and its general contents are determined by the Operation field. The actual format of the information is site or application specific, and a robust imple- mentation SHOULD support the field as undistinguished octets. The size is determined from the Length field. It is intended that only an authorized user will have correct site specific information to make use of the CallBack. The codifica- tion of the range of allowed usage of this field is outside the scope of this specification. Simpson expires in six months [Page 2] DRAFT PPP CallBack November 1996 Security Considerations Security issues are briefly discussed in sections concerning the CallBack Configuration Option. Acknowledgements Special thanks to Morning Star Technologies for providing computing resources and network access support for writing this specification. References [1] Simpson, W., Editor, "The Point-to-Point Protocol (PPP)", RFC-1661, December 1993. [2] Reynolds, J.K., Postel, J.B., "Assigned Numbers", RFC-1700, July 1992. [3] Simpson, W., Editor, "PPP in HDLC-like Framing", RFC-1662, December 1993. Simpson expires in six months [Page 3] DRAFT PPP CallBack November 1996 Contacts Comments about this document should be discussed on the ietf- ppp@merit.edu mailing list. This document is a submission to the Point-to-Point Protocol Working Group of the Internet Engineering Task Force (IETF). The working group can be contacted via the current chair: Karl Fox Ascend Communications 3518 Riverside Drive Suite 101 Columbus, Ohio 43221 karl@MorningStar.com karl@Ascend.com Questions about this document can also be directed to: William Allen Simpson DayDreamer Computer Systems Consulting Services 1384 Fontaine Madison Heights, Michigan 48071 wsimpson@UMich.edu wsimpson@GreenDragon.com (preferred) bsimpson@MorningStar.com Simpson expires in six months [Page 4]