Encapsulation Methods for Transport of PPP/High-Level Data Link Control (HDLC) over MPLS Networks
RFC 4618
Document | Type | RFC - Proposed Standard (September 2006; No errata) | |
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Authors | Andy Malis , Eric Rosen , Luca Martini , Giles Heron | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4618 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Mark Townsley | ||
Send notices to | (None) |
Network Working Group L. Martini Request for Comments: 4618 E. Rosen Category: Standards Track Cisco Systems, Inc. G. Heron A. Malis Tellabs September 2006 Encapsulation Methods for Transport of PPP/High-Level Data Link Control (HDLC) over MPLS Networks 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 Internet Society (2006). Abstract A pseudowire (PW) can be used to carry Point to Point Protocol (PPP) or High-Level Data Link Control (HDLC) Protocol Data Units over a Multiprotocol Label Switching (MPLS) network without terminating the PPP/HDLC protocol. This enables service providers to offer "emulated" HDLC, or PPP link services over existing MPLS networks. This document specifies the encapsulation of PPP/HDLC Packet Data Units (PDUs) within a pseudowire. Martini, et al. Standards Track [Page 1] RFC 4618 Transport of PPP/HDLC over MPLS September 2006 Table of Contents 1. Introduction ....................................................2 2. Specification of Requirements ...................................2 3. Applicability Statement .........................................5 4. General Encapsulation Method ....................................6 4.1. The Control Word ...........................................6 4.2. MTU Requirements ...........................................8 5. Protocol-Specific Details .......................................9 5.1. HDLC .......................................................9 5.2. Frame Relay Port Mode ......................................9 5.3. PPP .......................................................10 6. Using an MPLS Label as the Demultiplexer Field .................11 6.1. MPLS Shim EXP Bit Values ..................................11 6.2. MPLS Shim S Bit Value .....................................11 7. Congestion Control .............................................12 8. IANA Considerations ............................................12 9. Security Considerations ........................................12 10. Normative References ..........................................13 11. Informative References ........................................13 1. Introduction A PPP/HDLC pseudowire (PW) allows PPP/HDLC Protocol Data Units (PDUs) to be carried over an MPLS network. In addressing the issues associated with carrying a PPP/HDLC PDU over an MPLS network, this document assumes that a PW has been set up by some means outside the scope of this document. This may be via manual configuration, or using a signaling protocol such as that defined in [RFC4447]. The following figure describes the reference models that are derived from [RFC3985] to support the HDLC/PPP PW emulated services. The reader is also assumed to be familiar with the content of the [RFC3985] document. 2. Specification of Requirements The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Martini, et al. Standards Track [Page 2] RFC 4618 Transport of PPP/HDLC over MPLS September 2006 |<-------------- Emulated Service ---------------->| | | | |<------- Pseudowire ------->| | | | | | | | |<-- PSN Tunnel -->| | | | V V V V | V AC +----+ +----+ AC V +-----+ | | PE1|==================| PE2| | +-----+ | |----------|............PW1.............|----------| | | CE1 | | | | | | | | CE2 | | |----------|............PW2.............|----------| | +-----+ ^ | | |==================| | | ^ +-----+ ^ | +----+ +----+ | | ^ | | Provider Edge 1 Provider Edge 2 | |Show full document text