• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 1
Evolving Networks – Towards IP over WDM
• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 2
Evolving Networks – Towards IP over WDM
• Optical transport networks contain WDM signals, optical cross-connects for both wavelength and fiber switching, and optical add-drop multiplexers
• Optical transport networks provide data transport services for their client networks
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 3
Optical Transport Networks
Client Network Client Network
Optical TransportNetwork
OCX
OCX
OADM
OCX
OCX
OADM
OCX
• Overlay networks have separated control planes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 4
Overlay Networks Client
NetworkClient
Network
Transport Sub-Network
Client NetworksControl Plane Signals
Transport Sub-Network
Transport Sub-Network
Network-NetworkInterface
(NNI)
Network-NetworkInterface
(NNI)
User-NetworkInterface
(UNI)
User-NetworkInterface
(UNI)
Transport NetworkControl Plane Signals
Overlay Model
• Peer networks have a single, unified control plane
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 5
Peer Networks Client
NetworkClient
Network
Transport Sub-Network
Unified Control Plane Signals
Transport Sub-Network
Transport Sub-Network
Network-NetworkInterface
(NNI)
Network-NetworkInterface
(NNI)
User-NetworkInterface
(NNI)
User-NetworkInterface
(NNI)
Peer Model
• An evolved form of SONET • Supports the establishment of “light paths” end to end
connections on a single WDM wavelength • Strong forward error correction for error-free
transmission in noisy, high-speed, WDM environments • Designed to carry any client signal “transparently” (e.g.
Ethernet , ATM, SONET …) • Packets carry information to facilitate handoff between
administrative domains (networks controlled by different operators) OPTI 500, Spring 2011, Lecture 9, Evolving Networks 6
Optical Transport Network (OTN) Protocol Standard
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 7
OTN Network Layers
From ITU’s “Optical Transport Network (OTN) Tutorial,” Timothy P. Walker, http://www.itu.int/ITU-T/studygroups/com15/otn/OTNtutorial.pdf
Optical Layers OTS = Optical Transmission Section OMS = Optical Multiplexing Section OCh = Optical Channel
Electrical Layers OTU = Optical Channel Transport Unit ODU = Optical Channel Data Unit OPU = Optical Payload Unit
IrDI = Inter-Domain Interface IrAI = Intra-Domain Interface
Client Signals
Client Signals
OPU
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 8
OTN Optical Layers
• OTN layers manage the interfaces between the sections or channels they are named after
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 9
OTN Optical Layers
OTN Optical Frame
OpticalChannelHeader
Multiplex-ing
Header
Transmis-sion
Header
Client Payload(SONET, IP, Ethernet, …)
ForwardError
Correction
OCh Layer
OMS Layer
OTS Layer
Describes how EDFA vendors should handle
input and output
Handles end-to-end optical signals
Requirements for optical add-drop
multiplexers
• The Optical Multiplexing Section and Optical Transmission Section Layers are not defined in the ITU G.709 recommendation.
• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 10
Evolving Networks – Towards IP over WDM
• ASON is being developed in a series of ITU recommendations starting with: – G.807, “Requirements for Automatically Switched
Transport Networks,” July 2001 – G.8080, “Architecture of the Automatically Switched
Transport Network,” November 2001 • ASON builds on the Optical Transport Network
recommendations (e.g. G.709) by discussing signaling (i.e. control plane functions)
• ASON is an “overlay” model
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 11
Automatically Switched Optical Network (ASON)
• The ASON model has three basic units:
nodes, links, and subnetworks • The simplest subnetwork is a
single node • Subnetworks can contain
subnetworks • A subnetwork may be
represented as a virtual node
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 12
Automatically Switched Optical Network (ASON)
From GMPLS: Architecture and Applications , Adrian Farrel & Igor Bryskin
Nested subnetworks
• ASON defines a User-to-Network Interface (UNI), an Internal Network-to-Network Interface (I-NNI) and an External Network-to-Network Interface (E-NNI)
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 13
ASON Reference Points
From GMPLS: Architecture and Applications , Adrian Farrel & Igor Bryskin
• ASON describes, in general terms, signaling by way of calls and connections that are made across reference points
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 14
ASON Calls and Connections
From GMPLS: Architecture and Applications , Adrian Farrel & Igor Bryskin
• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 15
Evolving Networks – Towards IP over WDM
• Internet protocol tells us how to route across networks but does provide a way to do explicit routing (i.e. to establish virtual circuits) or how to ensure Quality of Service (QoS) for real time applications
• Multiprotocol Label Switching (MPLS), developed by IETF (the internet people) provides a way to add these functions, including establishing a “Label Switched Path” (LSP) by insertion of a “shim” header into a data frame.
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 16
Multiprotocol Label Switching
DataIP
(Layer 3)Header
MPLS“Shim”
Network(Layer 2)Header
• Generalized Multiprotocol Label Switching (GMPLS) extends the MPLS control functions to include switching of fibers, wavelengths, and TDM slots. OPTI 500, Spring 2011, Lecture 10, Evolving Networks 17
Generalized Multiprotocol Label Switching
From GMPLS: Architecture and Applications , Adrian Farrel & Igor Bryskin
• GMPLS provides a potential protocol for implementing the very general control plane architecture of the ASON
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 18
ASON and GMPLS
• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 19
Evolving Networks – Towards IP over WDM
• MPLS-TP is a recently established collaborative effort between ITU (the telecommunication and transport network people) and IETF (the internet people) to refine MPLS and GMPLS to be used for transport networks
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 20
Multiprotocol Label Switching – Transport Profile (MPLS-TP)
MPLS/ GMPLS
MPLS-TP
MPLS-TP Extensions
Overlap
• MPLS-TP emphasizes Operations, Administration, and Management (OAM) functions – Fault Detection – Performance Monitoring (A CIAN emphasis)
• MPLS-TP can be used without Internet Protocol
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 21
MPLS-TP: Key Extensions
• MPLS-TP supports “in-band” control signaling
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 22
MPLS-TP: Interesting Point Data
Packet ControlPacket
Data Packet
Data Packet
WDM Wavelength λ
Data Packet
ControlPacket
Data Packet
Data Packet
WDM Wavelength λ1
ControlPacket
Data Packet
WDM Wavelength λ2
In-Band Signaling
Out-of-Band Signaling
OPTI 500, Spring 2011, Lecture 10, Evolving Networks 23
Options for Implementing MPLS-TP
STB = Set Top Box PON = Passive Optical Network DSL = Digital Subscriber Line BNG = Broadband Network Gateway PE = Provider Edge ROADM = Reconfigurable Add-Drop Multiplexer VoD = Video on Demand TV = Television SIP = Session Initiated Protocol (phone calls, video conferencing)
Servers
• Optical Transport Networks • Overlay and Peer Networks • The ITU Optical Transport Network (OTN) Standard • Automatically Switched Optical Networks (ASON) • Generalized Multiprotocol Label Switching (GMPLS) • Multiprotocol Label Switching – Transport Profile
(MPLS-TP) • Multi-Service Network Nodes
OPTI 500, Spring 2011, Lecture 9, Evolving Networks 24
Evolving Networks – Towards IP over WDM
Multiservice Network Nodes
Financial Enterprise
…..
Broadband & Triple Play
Wireless Backhaul
Business Services
WDM
MSPP
Ethernet-Switched Packet Network
SONET/SDH, OTN Transport Network
PacketONP
PacketONP
PacketONP
PacketONP
MSPP
PacketONP
PacketONP
PacketONP
PacketONP
…..
CIAN Regime Core Transport Customer Premises
Aggregation Platform: Packet & TDM Svcs. + Optical transport
CIAN Box = All-optical (no OEO) switching node with built-in performance monitoring
Ethernet SONET WDM
Aggregation Network
MSPP = Multi Service Provisioning Platform ONP = Optical Networking Platform