From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc1619.txt | 334 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 334 insertions(+) create mode 100644 doc/rfc/rfc1619.txt (limited to 'doc/rfc/rfc1619.txt') diff --git a/doc/rfc/rfc1619.txt b/doc/rfc/rfc1619.txt new file mode 100644 index 0000000..47ad29b --- /dev/null +++ b/doc/rfc/rfc1619.txt @@ -0,0 +1,334 @@ + + + + + + +Network Working Group W. Simpson +Request for Comments: 1619 Daydreamer +Category: Standards Track May 1994 + + + PPP over SONET/SDH + + + +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. + This document describes the use of PPP over Synchronous Optical + Network (SONET) and Synchronous Digital Heirarchy (SDH) circuits. + + This document is the product of the Point-to-Point Protocol Working + Group of the Internet Engineering Task Force (IETF). Comments should + be submitted to the ietf-ppp@merit.edu mailing list. + + + +Applicability + + This specification is intended for those implementations which desire + to use the PPP encapsulation over high speed private point-to-point + links, such as intra-campus single-mode fiber which may already be + installed and unused. Because the PPP encapsulation has relatively + low overhead, it is anticipated that significantly higher throughput + can be attained compared to other SONET/SDH payload mappings, at a + significantly lower cost for line termination equipment. + + + + + + + + + + +Simpson [Page i] + RFC 1619 PPP over SONET/SDH May 1994 + + + Table of Contents + + + 1. Introduction .......................................... 1 + + 2. Physical Layer Requirements ........................... 1 + + 3. Framing ............................................... 2 + + 4. Configuration Details ................................. 3 + + SECURITY CONSIDERATIONS ...................................... 3 + + REFERENCES ................................................... 3 + + ACKNOWLEDGEMENTS ............................................. 3 + + CHAIR'S ADDRESS .............................................. 4 + + AUTHOR'S ADDRESS ............................................. 4 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Simpson [Page ii] + RFC 1619 PPP over SONET/SDH May 1994 + + +1. Introduction + + PPP was designed as a standard method of communicating over point- + to-point links. Initial deployment has been over short local lines, + leased lines, and plain-old-telephone-service (POTS) using modems. + As new packet services and higher speed lines are introduced, PPP is + easily deployed in these environments as well. + + This specification is primarily concerned with the use of the PPP + encapsulation over SONET/SDH links. Since SONET/SDH is by definition + a point-to-point circuit, PPP is well suited to use over these links. + + The Synchronous Optical Network (SONET) [3] is an octet-synchronous + multiplex scheme that defines a family of standard rates and formats. + Despite the name, it is not limited to optical links. Electrical + specifications have been defined for single-mode fiber, multi-mode + fiber, and CATV 75 ohm coaxial cable. The transmission rates are + integral multiples of 51.840 Mbps, which may be used to carry T3/E3 + bit-synchronous signals. The allowed multiples are currently + specified as + + STS-1 51.840 STS-18 933.120 + STS-3 155.520 STS-24 1,244.160 + STS-9 466.560 STS-36 1,866.240 + STS-12 622.080 STS-48 2,488.320 + + + The CCITT Synchronous Digital Heirarchy (SDH) defines a subset of + SONET transmission rates beginning at 155.520 Mbps [5]. + + SONET SDH equivalent + STS-3c STM-1 + STS-12c STM-4 + STS-48c STM-16 + + + + +2. Physical Layer Requirements + + PPP treats SONET/SDH transport as octet oriented synchronous links. + SONET/SDH links are full-duplex by definition. + + Interface Format + + PPP presents an octet interface to the physical layer. There is + no provision for sub-octets to be supplied or accepted. + + + + +Simpson [Page 1] + RFC 1619 PPP over SONET/SDH May 1994 + + + The octet stream is mapped into the SONET/SDH Synchronous Payload + Envelope (SPE), with the octet boundaries aligned with the SPE + octet boundaries. + + No scrambling is needed during insertion into the SPE. + + The Path Signal Label (C2) is intended to indicate the contents of + the SPE. The experimental value of 207 (cf hex) is used to + indicate PPP. + + The Multiframe Indicator (H4) is currently unused, and MUST be + zero. + + Transmission Rate + + The basic rate for PPP over SONET/SDH is that of STS-3c/STM-1 at + 155.520 Mbps. The available information bandwidth is 149.760 + Mbps, which is the STS-3c/STM-1 SPE with section, line and path + overhead removed. This is the same super-rate mapping that is + used for ATM and FDDI [4]. + + Lower signal rates MUST use the Virtual Tributary (VT) mechanism + of SONET/SDH. This maps existing signals up to T3/E3 rates + asynchronously into the SPE, or uses available clocks for bit- + synchronous and byte-synchronous mapping. + + Higher signal rates SHOULD conform to the SDH STM series, rather + than the SONET STS series, as equipment becomes available. The + STM series progresses in powers of 4 (instead of 3), and employs + fewer steps, which is likely to simplify multiplexing and + integration. + + Control Signals + + PPP does not require the use of control signals. When available, + using such signals can allow greater functionality and + performance. Implications are discussed in [2]. + + + +3. Framing + + The framing for octet-synchronous links is described in "PPP in HDLC + Framing" [2]. + + The PPP frames are located by row within the SPE payload. Because + frames are variable in length, the frames are allowed to cross SPE + boundaries. + + + +Simpson [Page 2] + RFC 1619 PPP over SONET/SDH May 1994 + + +4. Configuration Details + + The standard LCP sync configuration defaults apply to SONET/SDH + links. + + The following Configuration Options are recommended: + + Magic Number + No Address and Control Field Compression + No Protocol Field Compression + 32-bit FCS + + + + +Security Considerations + + Security issues are not discussed in this memo. + + + +References + + [1] Simpson, W., Editor, "The Point-to-Point Protocol (PPP)", RFC + 1548, Daydreamer, December 1993. + + [2] Simpson, W., Editor, "PPP in HDLC Framing", RFC 1549, + Daydreamer, December 1993. + + [3] "American National Standard for Telecommunications - Digital + Hierarchy - Optical Interface Rates and Formats Specification", + ANSI T1.105-1991. + + [4] "American National Standard for Telecommunications - + Synchronous Optical Network (SONET) Payload Mappings", ANSI + T1.105.02-1993 draft. + + [5] CCITT Recommendation G.707, "Synchronous Digital Hierarchy Bit + Rates", June 1992. + + + + + + + + + + + + +Simpson [Page 3] + RFC 1619 PPP over SONET/SDH May 1994 + + +Acknowledgments + + PPP over SONET was first proposed by Craig Partridge (BBN). Some + information was obtained from the good folks at Bellcore. + + Technical assistance and information was also provided by Victor + Demjanenko (SUNY Buffalo). + + Special thanks to Morning Star Technologies for providing computing + resources and network access support for writing this specification. + + + +Chair's Address + + The working group can be contacted via the current chair: + + Fred Baker + Advanced Computer Communications + 315 Bollay Drive + Santa Barbara, California 93117 + + EMail: fbaker@acc.com + + + +Author's Address + + Questions about this memo can also be directed to: + + William Allen Simpson + Daydreamer + Computer Systems Consulting Services + 1384 Fontaine + Madison Heights, Michigan 48071 + + EMail: Bill.Simpson@um.cc.umich.edu + bsimpson@MorningStar.com + + + + + + + + + + + + + +Simpson [Page 4] + + -- cgit v1.2.3