Network Working Group A. Malis
Request for Comments: 4842 Verizon Communications
Category: Standards Track P. Pate
Overture Networks
R. Cohen, Ed.
Resolute Networks
D. Zelig
Corrigent Systems
April 2007
Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH)
Circuit Emulation over Packet (CEP)
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 IETF Trust (2007).
Abstract
This document provides encapsulation formats and semantics for
emulating Synchronous Optical Network/Synchronous Digital Hierarchy
(SONET/SDH) circuits and services over MPLS.
Malis, et al. Standards Track [Page 1]
RFC 4842 SONET/SDH Circuit Emulation April 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Requirements Notation . . . . . . . . . . . . . . . . . . . . 4
4. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. CEP Encapsulation Format . . . . . . . . . . . . . . . . . . . 5
5.1. SONET/SDH Fragment . . . . . . . . . . . . . . . . . . . . 6
5.2. CEP Header . . . . . . . . . . . . . . . . . . . . . . . . 7
5.3. RTP Header . . . . . . . . . . . . . . . . . . . . . . . . 9
5.4. PSN Encapsulation . . . . . . . . . . . . . . . . . . . . 11
6. CEP Operation . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. CEP Packetizer and De-Packetizer . . . . . . . . . . . . . 11
6.2. Packet Synchronization . . . . . . . . . . . . . . . . . . 12
6.2.1. Acquisition of Packet Synchronization . . . . . . . . 13
6.2.2. Loss of Packet Synchronization . . . . . . . . . . . . 13
7. SONET/SDH Maintenance Signals . . . . . . . . . . . . . . . . 13
7.1. SONET/SDH to PSN . . . . . . . . . . . . . . . . . . . . . 13
7.1.1. CEP-AIS: AIS-P/V Indication . . . . . . . . . . . . . 13
7.1.2. Unequipped Indication . . . . . . . . . . . . . . . . 14
7.1.3. CEP-RDI: Remote Defect Indication . . . . . . . . . . 15
7.2. PSN to SONET/SDH . . . . . . . . . . . . . . . . . . . . . 15
7.2.1. CEP-AIS: AIS-P/V Indication . . . . . . . . . . . . . 15
7.2.2. Unequipped Indication . . . . . . . . . . . . . . . . 16
8. SONET/SDH Transport Timing . . . . . . . . . . . . . . . . . . 16
9. SONET/SDH Pointer Management . . . . . . . . . . . . . . . . . 17
9.1. Explicit Pointer Adjustment Relay (EPAR) . . . . . . . . . 17
9.2. Adaptive Pointer Management (APM) . . . . . . . . . . . . 19
10. CEP Performance Monitors . . . . . . . . . . . . . . . . . . . 19
10.1. Near-End Performance Monitors . . . . . . . . . . . . . . 19
10.2. Far-End Performance Monitors . . . . . . . . . . . . . . . 20
11. Payload Compression Options . . . . . . . . . . . . . . . . . 20
11.1. Dynamic Bandwidth Allocation . . . . . . . . . . . . . . . 21
11.2. Service-Specific Payload Formats . . . . . . . . . . . . . 21
11.2.1. Fractional STS-1 (VC-3) Encapsulation . . . . . . . . 21
11.2.1.1. Fractional STS-1 CEP Header . . . . . . . . . . . 23
11.2.1.2. B3 Compensation . . . . . . . . . . . . . . . . . 24
11.2.1.3. Actual Payload Size . . . . . . . . . . . . . . . 24
11.2.2. Asynchronous T3/E3 STS-1 (VC-3) Encapsulation . . . . 25
11.2.2.1. T3 Payload Compression . . . . . . . . . . . . . 25
11.2.2.2. E3 Payload Compression . . . . . . . . . . . . . 26
11.2.3. Fractional VC-4 Encapsulation . . . . . . . . . . . . 26
11.2.3.1. Fractional VC-4 Mapping . . . . . . . . . . . . . 27
11.2.3.2. Fractional VC-4 CEP Header . . . . . . . . . . . 28
11.2.3.3. B3 Compensation . . . . . . . . . . . . . . . . . 29
11.2.3.4. Actual Payload Sizes . . . . . . . . . . . . . . 30
12. Signaling of CEP Pseudowires . . . . . . . . . . . . . . . . . 30
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