12/15/2000 49th IETF

Carriers Service Framework and Associated UNI Requirements

Yong Xue

yxue@uu.netUUNET/WorldCom

12/15/2000 49th IETF

Document and Authors

Internet-Draft: <draft-many-carrier-framework-uni-00.txt>

Yong Xue , Daniel Awduche UUNET/WorldComMonica Lazer, John Strand, Jennifer Yates AT&TLarry McAdams CiscoOlga Aparicio, Roderick Dottin Cable & WirelessRahul Aggarwal Redback Networks

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About This Document

Contains the carrier optical service framework and major requirements developed by OIF Carrier Study Group

These requirements have been used to guide OIF UNI1.0 development and liaisoned to T1X1.5 and ITU SG 13 as input to ITU G.Ason development.

Still a work-in-progress document. Addressing issues of most concern in carriers community and not meant to be complete and comprehensive at this stage.

Cover more than just IP client

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Carriers Major Concerns

Viable optical business and service models UNI and optical connection requirements Network reference models and support Security is a big concern: resource and access

control Control plane functions w.r.t UNI Scalability

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Carriers Objectives

Promote a standardized optical control plane with its associated interfaces and protocols to achieve multi-vendor/multi-carrier interoperability.

Provide rapid automatic end-to-end provisioning of optical connection across one or more optical networks.

Support different service and business models including “branded” services, bandwidth-on-demand services , and Optical VPN (OVPN).

Support multiple different client signal types, including IP, ATM, PDH PL, SONET/SDH, and transparent signals

Promote policy-based call acceptance, peering policies and access/resource control.

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Carriers Objectives

Support the scalability both at node and network level: several thousands of ports per node and hundreds of switch nodes per network.

Provide restoration, diverse routing and other Qos features within the control plane on a per-service-path basis.

Reduce the need and cost for carrier developed OSS software development

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Optical Network

ONE

ONEONE

ONE

ED

ED

ED

ONE-SR

Sub-rateConnections

Sub-rateConnections

ED : Client Edge DeviceONE : Optical Network Element

Optical Service Path

Optical Lightpath

Optical Lightpath: : ONE-to-ONEOptical Service Path : ED-to-ED

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Optical Network

Major Components Optical Network Elements (ONE): OXC, OADM User Edge Device (UED): IP Router, ATM, FR, SONET Sub-networks DWDM Optical Line System (OLS)

Network Access Methods Cross-office (co-located) Inter-office (remote) Via third-party carrier

Abstract Model: A set of ingress/egress ports and a well-defined set of p2p optical connection services.

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Basic Optical Service Models Provisioned Bandwidth Service (PBS)

“Point and click” and static near-real-time provisioning through management interface (via NMS or OSS)

Client/Server relationship between clients and optical network

Customer has no network visibility and depends on network intelligence.

Bandwidth on Demand Service (BODS) Signaled connection request via UNI Dynamic and real-time provisioning in seconds or sub-

seconds Customer has no, limited or full network visibility depending

upon interconnecting and control model used Rely on network or client intelligence based on the

interconnecting and control model used

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Basic Optical Service Models

Optical Virtual Private Network (OVPN) Customers contract for specific set network resources

such as link bandwidth, wavelength, and/or optical connection ports.

Closed User Group (CUS) and virtual network Optical connection can be based on signaled or static

provisioning Customer may have limited visibility and control of

contracted network resources

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Optical Connection Services

Service Definition: A fixed bandwidth connection between an ingress port

and an egress port across the optical transport network.

Optical Connection Behavior Defined by its Attributes: identification-based: unique connection ID, contract ID,

user group ID, source and destination identifiers (address, port, channel and sub-channel)

characteristics-based: framing ( type, bandwidth, transparency, directionality), priority, protection (1+1, 1:n, unprotected, etc.), scheduling and service level.

Routing-based: diversity

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Optical Connection Services

Optical Connection Operations Requests to create, delete, modify and query an

optical connection Only non-destructive attribute modification is

allowed. A status code should be returned for each operation

request. Same functions should be available via management

interface

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Service Requirements Service Type and Granularity

SONET/SDH: STS-n/STM-m OC-48/STM-16 & OC-192/STM-64 OC-768/STM-256

Ethernet: 1Gb/s E, 10Gb/s E (LAN and WAN mode) PDH: DS1/E1, DS3/E3, … Other Choices

Sub-rates multiplexed interfaces (both channelized and concatenated)

G.709 digital wrapper, selectable rates interfaces, composite interfaces

Interface Type vs. Service Type

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Service Requirements Addressing Schema

Separation of client network and optical network address space

Provisioning based on the client address or names, including IP, NSAP and E.164

Address resolution and address translation service should be provided by the optical network.

Qos Service Mapping from SLA Contract Service provider has flexibility to map different class

of services (COS) to its own set of priority, protection, restoration parameters.

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Sub-Rate Service Framework

Wavelength (Lambda) switching at DWMD channel rate ( OC-48/STM-16 and up) in optical domain.

Sub-Rate: switched at less than 2.5Gb/s switching in the

electrical domain Sub-rate extension to UNI: UNI-SR Separate process for ONE-SR

ONE-SR Multiplexing/demultiplexing Mapping and adaptation Possible implementation: separate box or software

process

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Sub-Rate Service Framework

<= 2.5 Gb/s >= 2.5 Gb/s

<= 2.5 Gb/s >= 10 Gb/s

O NE-SR

ED(ST S-m N ,

ST M -N ,VC -K ,VT -X )

O NE

Granularity >=2.5 Gb/s

Granularity<=2.5 Gb/s

O ptica l Service Path

O ptica l L ightpath

UNIUNI-SR

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Network Reference Model

An Optical Network Can be Decomposed into Three Logical Network Planes

User Data Plane (U-Plane) Control Plane (C-Plane) Management Plane (M-Plane)

Each Logical Network Plane Consists of A plane-specific set of networking functions A transport network

Optical Networking Function optical connection routing optical connection switching optical connection multiplexing/demultiplexing optical connection protection and restoration

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Carrier Network Reference Model

Consists of one or more sub-networks With equipment from single or multiple vendors With equipment based on single or multiple

technologies Interfaces Reference Points

User-Network Interface (UNI) and Network-Network Interface (NNI)

Private vs. Public UNI/NNI: Based on trust relationship between interconnected optical domains

Data Service Interface (DSI) UNI Sub-rate (UNI-SR)

Inter-carrier vs. Intra-carrier model

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Inter-Carrier Network Model

Carrier AOptical Network

Carrier COptical Network

Carrier BOptical Network

ED ED

ED ED

ED

ED

EDED

PUB-UNI

PUB-UNI

PUB-UNIPUB-UNI

PUB-UNI

PUB-UNI

PUB-UNI

PUB-NNI

PUB-NNIPUB-NNI

ED :Client's Edge DevicePUB-UNI/NNI :Public UNI/NNIPRI-UNI/NNI :Private UNI/NNI

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Intra-Carrier Network Model

ED

OpticalSub-Network

OpticalSub-Network

OpticalSub-Network

ED

CED CED

CED

ED

ED

ED

ED

Vendor AOptical network

DSI

DSI

DSI

DSI

PRI-NNI

PRI-NNIPRI-NNI

PRI-UNI

PRI-UNIPRI-UNI

PUB-UNI

PUB-UNI

PUB-UNIPUB-UNI

PUB-UNI

PUB-NNI 3rd PartyNetwork

ED :Client Edge DeviceCED :Carrier Edge DevicePUB-UNI/NNI :Public UNI/NNIPRI-UNI/NNI :Private UNI/NNIDSI :Data Service Interface (ATM, SONET, etc.)

PUB-UNI

PUB-NNI

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Control Plane Architecture Control Plane Functions

Signaling and Routing Resource, end-systems and service discovery End-to-end auto optical connection provisioning, tear-

down, and management Support direct switching cross-connect provisioning for

permanent connection Support various optical connection protection and

restoration schema Control Plane Function Access Support via:

UNI NNI NMS/EMS

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UNI Signaling Model

UNI-C and UNI-N Control Process Functional entities for signaling associated with client-side

ED and network-side ONE. Tightly-coupled vs. loosely-coupled.

Signaling Methods IN-Band:Signaling messages carried over a logical

communication channel embedded in the data-carrying optical link or channel between UNI-C and UNI-N

Out-of-Band: Signaling messages carried over a dedicated communication channel or fiber path separate from the data-carrying optical link or channel between UNI-C and UNI-N

In-Fiber vs. Out-of-Fiber Third-party Signaling: UNI-C is non-ED resident and directly

communicates with UNI-N of ONE on behalf of ED.

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Service and End-System Discovery

Service Discovery Querying and Signaling to ED available services and

parameters Support automatic service request and provisioning Carried by the service discovery protocol

End-System Discovery Auto identification between ONE and ED, and between ONEs Link connection state discovery Auto address registration/de-registration Carried by the service discovery protocol Exchange of defined set of local topological and identity

information Exchanged information accessible via management interface

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Routing Functions and Models Routing Function:

Dissemination and propagation of reachability, resource, and topological information.

Optical connection path computation. Route Generation

Static configuration Route server Dynamic learning via routing protocol

Routing Model Overlay, Peer and Augmented Carriers are very sensitive to routing model selection due

to security and scalability concerns. Configurable and enforceable routing control policy should

be supported at UNI/NNI

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Routing Functions and Models

Overlay Model Optical network and client networks are independent

routing domains No routing information exchanged at UNI/NNI Required support at both private UNI/NNI and Public

UNI/NNI Peer Model

Optical network and client networks are integrated routing domains and running the same routing protocol

Full or partial routing information exchanged at UNI/NNI

Support only allowed at private UNI/NNI Some possible scaling issues

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Routing Functions and Models

Augmented Model Optical network and client networks are independent

routing domains Only client network reachabilty information carried

across optical network and advertised to other clients.

An inter-domain routing protocol used at UNI/NNI May be supported at both private UNI/NNI and public

UNI/NNI

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Routing Constraint Support

Diversity Shared Risk Link Group (SRLG) K-out-of N Diversity Hierarchical and Geographic Diversity

(Node/Network/Location) Channel Grouping

TDM Multiplexed Sub-channels Bundling Wavelength Grouping (Waveband)

Edge Compatibility Laser Frequency Compatible Adaptation Functions User/Peer Group

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Security and Access Control Trust Relationship Between Network and Clients as Well as

Between Two Networks Trusted vs. untrusted relation Distinguish between private and public UNI/NNI

interfaces at network demarcation points. Policy-Based Control

Configurable and enforceable policy-based access/resource control at UNI/NNI Interfaces

Different policy defined at private and public interfaces Service Request Authentication and Authorization Network Resources Information Access Control Firewall between UNI and NNI

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Questions ?

Thanks!