Evolving Networks – Towards IP over...

• 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 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


Optical Transport Networks

Client Network Client Network

Optical TransportNetwork

OCX

OCX

OADM

OCX

OCX

OADM

OCX

• Overlay networks have separated control planes


Overlay Networks Client

NetworkClient

Network

Transport Sub-Network

Client NetworksControl Plane Signals



Network-NetworkInterface

(NNI)


(NNI)

User-NetworkInterface

(UNI)


(UNI)

Transport NetworkControl Plane Signals

Overlay Model

• Peer networks have a single, unified control plane


Peer Networks Client

NetworkClient

Network


Unified Control Plane Signals




(NNI)


(NNI)


(NNI)


(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


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


OTN Optical Layers

• OTN layers manage the interfaces between the sections or channels they are named after


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.

• 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


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


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)


ASON Reference Points


• ASON describes, in general terms, signaling by way of calls and connections that are made across reference points


ASON Calls and Connections


• 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.


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


• GMPLS provides a potential protocol for implementing the very general control plane architecture of the ASON


ASON and GMPLS

• 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


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


MPLS-TP: Key Extensions

• MPLS-TP supports “in-band” control signaling


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


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

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

• CIAN’s Testbed for Optical Integration (TOAN) includes two Flashwave 9500 packet optical networking platforms. OPTI 500, Spring 2011, Lecture 10, Evolving Networks 26

Fujitsu’s Packet Optical Networking Platform

Evolving Networks – Towards IP over...

Documents

Transcript of Evolving Networks – Towards IP over...