Carrier Requirements

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Carriers Service Framework and Associated UNI
Requirements Yong Xue yxue_at_uu.net UUNET/WorldC
om
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Document and Authors

• Internet-Draft ltdraft-many-carrier-framework-uni-
  00.txtgt
• Yong Xue , Daniel Awduche
  UUNET/WorldCom
• Monica Lazer, John Strand, Jennifer Yates
  ATT
• Larry McAdams Cisco
• Olga Aparicio, Roderick Dottin Cable
  Wireless
• Rahul 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
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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 (11, 1n, 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
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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
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Intra-Carrier Network Model
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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-BandSignaling 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!