Requirements for Generalized MPLS (GMPLS) Signaling Usage and Extensions for Automatically Switched Optical Network (ASON)
RFC 4139
Network Working Group D. Papadimitriou
Request for Comments: 4139 Alcatel
Category: Informational J. Drake
Boeing
J. Ash
ATT
A. Farrel
Old Dog Consulting
L. Ong
Ciena
July 2005
Requirements for Generalized MPLS (GMPLS) Signaling Usage
and Extensions for Automatically Switched Optical Network (ASON)
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
The Generalized Multi-Protocol Label Switching (GMPLS) suite of
protocols has been defined to control different switching
technologies and different applications. These include support for
requesting Time Division Multiplexing (TDM) connections, including
Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy
(SDH) and Optical Transport Networks (OTNs).
This document concentrates on the signaling aspects of the GMPLS
suite of protocols. It identifies the features to be covered by the
GMPLS signaling protocol to support the capabilities of an
Automatically Switched Optical Network (ASON). This document
provides a problem statement and additional requirements for the
GMPLS signaling protocol to support the ASON functionality.
Papadimitriou, et al. Informational [Page 1]
RFC 4139 GMPLS Signaling Usage and Extensions for ASON July 2005
1. Introduction
The Generalized Multi-Protocol Label Switching (GMPLS) suite of
protocol specifications provides support for controlling different
switching technologies and different applications. These include
support for requesting Time Division Multiplexing (TDM) connections,
including Synchronous Optical Network (SONET)/Synchronous Digital
Hierarchy (SDH) (see [ANSI-T1.105] and [ITU-T-G.707], respectively),
and Optical Transport Networks (see [ITU-T-G.709]). In addition,
there are certain capabilities needed to support Automatically
Switched Optical Networks control planes (their architecture is
defined in [ITU-T-G.8080]). These include generic capabilities such
as call and connection separation, along with more specific
capabilities such as support of soft permanent connections.
This document concentrates on requirements related to the signaling
aspects of the GMPLS suite of protocols. It discusses the functional
requirements required to support Automatically Switched Optical
Networks that may lead to additional extensions to GMPLS signaling
(see [RFC3471] and [RFC3473]) to support these capabilities. In
addition to ASON signaling requirements, this document includes GMPLS
signaling requirements that pertain to backward compatibility
(Section 5). A terminology section is provided in the Appendix.
2. Conventions Used in This Document
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].
While [RFC2119] describes interpretations of these key words in terms
of protocol specifications and implementations, they are used in this
document to describe design requirements for protocol extensions.
3. Problem Statement
The Automatically Switched Optical Network (ASON) architecture
describes the application of an automated control plane for
supporting both call and connection management services (for a
detailed description see [ITU-T-G.8080]). The ASON architecture
describes a reference architecture, (i.e., it describes functional
components, abstract interfaces, and interactions).
The ASON model distinguishes reference points (representing points of
information exchange) defined (1) between a user (service requester)
and a service provider control domain, a.k.a. user-network interface
(UNI), (2) between control domains, a.k.a. external network-network
interface (E-NNI), and, (3) within a control domain, a.k.a. internal
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RFC 4139 GMPLS Signaling Usage and Extensions for ASON July 2005
network-network interface (I-NNI). The I-NNI and E-NNI interfaces
are between protocol controllers, and may or may not use transport
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