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diff --git a/doc/rfc/rfc1764.txt b/doc/rfc/rfc1764.txt new file mode 100644 index 0000000..f949f36 --- /dev/null +++ b/doc/rfc/rfc1764.txt @@ -0,0 +1,283 @@ + + + + + + +Network Working Group S. Senum +Request for Comments: 1764 DigiBoard +Category: Standards Track March 1995 + + + The PPP XNS IDP Control Protocol (XNSCP) + +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. + +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, and proposes a family of + Network Control Protocols for establishing and configuring different + network-layer protocols. + + This document defines the Network Control Protocol for establishing + and configuring the Xerox Network Systems (XNS) Internet Datagram + Protocol (IDP) over PPP. + +Table of Contents + + 1. Introduction .......................................... 2 + 1.1 Specification of Requirements ................... 2 + 1.2 Terminology ..................................... 3 + 2. A PPP Network Control Protocol for XNS IDP ............ 3 + 2.1 Sending XNS IDP Datagrams ....................... 4 + SECURITY CONSIDERATIONS ...................................... 5 + REFERENCES ................................................... 5 + ACKNOWLEDGEMENTS .......................................... 5 + CHAIR'S ADDRESS .............................................. 5 + AUTHOR'S ADDRESS ............................................. 5 + + + + + + + + + + + + +Senum [Page 1] + +RFC 1764 PPP XNSCP March 1995 + + +1. Introduction + + PPP has three main components: + + 1. A method for encapsulating multi-protocol datagrams. + + 2. A Link Control Protocol (LCP) for establishing, configuring, + and testing the data-link connection. + + 3. A family of Network Control Protocols for establishing and + configuring different network-layer protocols. + + In order to establish communications over a point-to-point link, each + end of the PPP link must first send LCP packets to configure and test + the data link. After the link has been established and optional + facilities have been negotiated as needed by the LCP, PPP must send + XNSCP packets to choose and configure the XNS IDP network-layer + protocol. Once XNSCP has reached the Opened state, XNS IDP datagrams + can be sent over the link. + + The link will remain configured for communications until explicit LCP + or XNSCP packets close the link down, or until some external event + occurs (an inactivity timer expires or network administrator + intervention). + +1.1. Specification of Requirements + + In this document, several words are used to signify the requirements + of the specification. These words are often capitalized. + + MUST This word, or the adjective "required", means that the + definition is an absolute requirement of the specification. + + MUST NOT This phrase means that the definition is an absolute + prohibition of the specification. + + SHOULD This word, or the adjective "recommended", means that there + may exist valid reasons in particular circumstances to + ignore this item, but the full implications must be + understood and carefully weighed before choosing a + different course. + + MAY This word, or the adjective "optional", means that this + item is one of an allowed set of alternatives. An + implementation which does not include this option MUST be + prepared to interoperate with another implementation which + does include the option. + + + + +Senum [Page 2] + +RFC 1764 PPP XNSCP March 1995 + + +1.2. Terminology + + This document frequently uses the following terms: + + datagram The unit of transmission in the network layer (such as IP). + A datagram may be encapsulated in one or more packets + passed to the data link layer. + + frame The unit of transmission at the data link layer. A frame + may include a header and/or a trailer, along with some + number of units of data. + + packet The basic unit of encapsulation, which is passed across the + interface between the network layer and the data link + layer. A packet is usually mapped to a frame; the + exceptions are when data link layer fragmentation is being + performed, or when multiple packets are incorporated into a + single frame. + + peer The other end of the point-to-point link. + + silently discard + This means the implementation discards the packet without + further processing. The implementation SHOULD provide the + capability of logging the error, including the contents of + the silently discarded packet, and SHOULD record the event + in a statistics counter. + +2. A PPP Network Control Protocol for XNS IDP + + The XNS IDP Control Protocol (XNSCP) is responsible for configuring, + enabling, and disabling the XNS IDP protocol modules on both ends of + the point-to-point link. XNSCP uses the same packet exchange + mechanism as the Link Control Protocol (LCP). XNSCP packets may not + be exchanged until PPP has reached the Network-Layer Protocol phase. + XNSCP packets received before this phase is reached should be + silently discarded. + + The XNS IDP Control Protocol is exactly the same as the Link Control + Protocol [1] with the following exceptions: + + Frame Modifications + + The packet may utilize any modifications to the basic frame format + which have been negotiated during the Link Establishment phase. + + + + + + +Senum [Page 3] + +RFC 1764 PPP XNSCP March 1995 + + + Data Link Layer Protocol Field + + Exactly one XNSCP packet is encapsulated in the Information field + of a PPP Data Link Layer frame, where the PPP Protocol field + indicates type hex 8025 (XNS IDP Control Protocol). + + Code field + + Only Codes 1 through 7 (Configure-Request, Configure-Ack, + Configure-Nak, Configure-Reject, Terminate-Request, Terminate-Ack + and Code-Reject) are used. Other Codes should be treated as + unrecognized and should result in Code-Rejects. + + Timeouts + + XNSCP packets may not be exchanged until PPP has reached the + Network-Layer Protocol phase. An implementation should be + prepared to wait for Authentication and Link Quality Determination + to finish before timing out waiting for a Configure-Ack or other + response. It is suggested that an implementation give up only + after user intervention or a configurable amount of time. + + Configuration Option Types + + XNSCP has no Configuration Options. + +2.1. Sending XNS IDP Datagrams + + Before any XNS IDP packets may be communicated, PPP must reach the + Network-Layer Protocol phase, and the XNS IDP Control Protocol must + reach the Opened state. + + Exactly one XNS IDP packet is encapsulated in the Information field + of a PPP Data Link Layer frame where the Protocol field indicates + type hex 0025 (XNS IDP datagram). + + The maximum length of a XNS IDP datagram transmitted over a PPP link + is the same as the maximum length of the Information field of a PPP + data link layer frame. Since there is no standard method for + fragmenting and reassembling XNS IDP datagrams, PPP links supporting + XNS IDP MUST allow at least 576 octets in the information field of a + data link layer frame. + + The format of the Information field itself is the same as that + defined in [2]. + + + + + + +Senum [Page 4] + +RFC 1764 PPP XNSCP March 1995 + + +Security Considerations + + Security issues are not discussed in this memo. + +References + + [1] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, RFC + 1661, Daydreamer, July 1994. + + [2] Xerox, "Internet Transport Protocols", January 1991, Order No. + XNSS 029101. + +Acknowledgements + + Some of the text in this document is taken from previous documents + produced by the Point-to-Point Protocol Working Group of the Internet + Engineering Task Force (IETF). + + In particular, Bill Simpson provided the boiler-plate used to create + this document. + +Chair's Address + + The working group can be contacted via the current chair: + + Fred Baker + Cisco Systems + 519 Lado Drive + Santa Barbara, California 93111 + + Phone: (805) 681-0115 + EMail: fred@cisco.com + +Author's Address + + Questions about this memo can also be directed to: + + Steven J. Senum + DigiBoard + 6400 Flying Cloud Drive + Eden Prairie, Minnesota 55344 + + Phone: (612) 943-9020 + EMail: sjs@digibd.com + + + + + + + +Senum [Page 5] + |