PPP Link Quality Monitoring
RFC 1333
Document | Type |
RFC - Proposed Standard
(May 1992; No errata)
Obsoleted by RFC 1989
|
|
---|---|---|---|
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text pdf html bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1333 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group W. Simpson Request for Comments: 1333 Daydreamer May 1992 PPP Link Quality Monitoring Status of this Memo This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" 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 of encapsulating Network Layer protocol information over point-to-point links. PPP also defines an extensible Link Control Protocol, which allows negotiation of a Quality Protocol for continuous monitoring of the viability of the link. This document defines a protocol for generating Link-Quality-Reports. This RFC is a product of the Point-to-Point Protocol Working Group of the Internet Engineering Task Force (IETF). Comments on this memo should be submitted to the ietf-ppp@ucdavis.edu mailing list. Simpson [Page i] RFC 1333 PPP Link Quality Monitoring May 1992 Table of Contents 1. Introduction .......................................... 1 2. Link Quality Monitoring ............................... 2 2.1 Design Motivation ............................... 2 2.2 Counters ........................................ 2 2.3 Counting Packets and Octets ..................... 4 2.4 Processes ....................................... 4 2.5 Configuration Option Format ..................... 6 2.6 Packet Format ................................... 8 2.7 Transmission of Reports ......................... 12 2.8 Calculations .................................... 12 2.9 Failure Detection ............................... 13 2.10 Policy Suggestions .............................. 14 SECURITY CONSIDERATIONS ...................................... 14 REFERENCES ................................................... 14 ACKNOWLEDGEMENTS ............................................. 14 CHAIR'S ADDRESS .............................................. 15 AUTHOR'S ADDRESS ............................................. 15 Simpson [Page ii] RFC 1333 PPP Link Quality Monitoring May 1992 1. Introduction PPP has three main components: 1. A method for encapsulating datagrams over serial links. 2. A Link Control Protocol (LCP) for establishing, configuring, and testing the data-link connection. 3. A family of Network Control Protocols (NCPs) 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 the data link during the Establishment phase. During the Authentication and Network-Layer Protocol phases, the link may be tested to determine if quality is sufficient for operation. This testing is completely optional. If an implementation desires that the peer use some specific link quality monitoring protocol, then it MUST negotiate the use of that protocol using the Quality-Protocol Configuration Option during Link Establishment phase. The negotiation mechanism is independent in each direction. However, if the peer agrees to send Quality-Protocol packets, it MUST correctly process such packets on reception, even if it does not request such packets or implement a monitoring policy. Simpson [Page 1] RFC 1333 PPP Link Quality Monitoring May 1992 2. Link Quality Monitoring Data communications links are rarely perfect. Packets can be dropped or corrupted for various reasons (line noise, equipment failure, buffer overruns, etc.). Sometimes, it is desirable to determine when, and how often, the link is dropping data. Routers, for example, may want to temporarily allow another route to take precedence. An implementation may also have the option of disconnecting and switching to an alternate link. The process of determining data loss is called "Link Quality Monitoring". 2.1. Design Motivation There are many different ways to measure link quality, and even more ways to react to it. Rather than specifying a single scheme, Link Quality Monitoring is divided into a "mechanism" and a "policy". PPPShow full document text