광인터넷 망관리를 위한 주요 이슈

1. 광인터넷 망관리를 위한 주요 이슈 Jun Kyun Choi jkchoi@icu.ac.kr Tel) (042) 866-6122

2. 목차 • Requirements for Next Generation Network • Backgrounds for Optical Networking • IP over Optical Network Architecture • Management Requirements for Optical Internet • Generalized MPLS Technology for Optical Internet • Conclusions

3. Vision of Next Generation Infrastructure • Future network will be built using DWDM and MPLS • Long-haul network consist of a meshed network of optical cross-connects by DWDM system. The signaling will be based on MPLambdaS • Terabit Router will be deployed at the gateway or super POPs • Core Metro Network will be based on DWDM Optical Ring • A specialized router functioning as an IP service switch at each POP • Last mile consist of various technologies including ADSL, fixed wireless, PON, FTTC. Packet-enabled DWDM Metro/Regional Network Packet-enabled DWDM Metro/Regional Network Wireless (HFR) Integrated Access Network Integrated Access Network DWDM Backbone Network Wireless (HFR) PON PON 광선로 광선로 ADSL ADSL Cable (HFC) Cable (HFC) Access Metro/Regional Long haul Metro/Regional Access

4. Customers Requirements for Multi-Services • Security, predictability, and reliability • Cost effectiveness and flexibility • Applications that work all the time – end to end QoS • High reliability for mission critical applications

5. Requirements of Next Generation Infrastructure • High performance, scalable, efficient network • Always-available network (99.999 %) • Low cost administration nets • Scalable systems (small footprint, low power) • Auto provisioning • Fast troubleshooting & reaction to problems • Fast service activation • Up- to- date network knowledge • Policy-based management

6. Service Provider Objectives • Maximize revenue opportunities from optical network investments • Create new revenue opportunities, while avoiding the loss of existing revenue streams • Efficiency and reduced capital and operational costs through convergence and consolidation • Multiple networks create unnecessary duplication of effort and expertise in a single organization • Ease and automation of service provisioning • Faster and less expensive

7. Backgrounds for Optical Network • Re-evaluation of traditional network platforms and cost structures • Requirements changing on Service delivery and OAM • Limitations of existing architecture • Existing SONET/SDH ring-based architecture moves to Mesh configuration • Optimized for voice, Can’t scale enough for data • Utilize dynamic allocation for DWDM network capacity • Just-in-time provisioning for Dynamic Re-configurable Optical Network • Innovation and advances in optical components and transport technologies • Increased focus between electrical and optical devices

8. Dynamic Provisioning ? • Dynamic just in time provisioning • Efficient management of network assets • Migrating service provisioning responsibilities into the network and offloading the network management systems • A variety of protection and restoration options • Interoperability across multi-vendor, multi-technology, and multi-domain networks

9. Motivation for Optical Networking • Cost and Efficiencies • Wavelengths cheaper than switching packets • Eliminates costly O/E/O conversions and equipments • Flexibility and Management • Just-in-time service provisioning ? • Traffic engineering at the wave level ? • Revenue Opportunities • Fast provisioned wave services • Bursty IP services through backbone network

10. Toward Optical IP Network • Guidelines and Direction • Optical bandwidth reduces the cost of IP services • Use of Generalized MPLS signaling • Desire to have restoration behavior of current SONET network • Goal of dynamic optical path service • Greater bandwidth efficiency from IP layers

11. Control Requirements for Optical Networking • Dynamic Reconfiguration of Optical Network • Link Protection and restoration, Capacity Planning, performance monitoring, etc. • Rapid service provisioning for negotiated bandwidth and QoS • Scalability on bandwidth provisioning • Grooming of sub-rate circuits • Dynamic Optical VPN for multicast according to SLA • Automatic configuration and topology auto-discovery • Integrated control of L1, L2 and L3 Switching/Routing

12. Separation of Control Plane from Data Plane • Separate control and data channels • Out of band in fiber, out of band out of fiber • Control channel failure might not disrupt data • Control plane reboot might not disturb data plane • Handling Protection and Repair Conditions • Selection of Protection Domains • Requirements for Recovery • Failure Detection and Reporting • Recovery after Node Failure

13. WDM Layer WDM Layer WDM Layer Optical Layer Optical Layer Optical Layer Protocol Reference Model for Optical Internet Telecommunication Management Network Routing and Signalling Network M-plane M-plane M-plane U-plane C-plane U-plane C-plane U-plane C-plane IP Routing IP Routing IP Routing IP Signalling (SIP,etc) IP Layer IP Signalling (SIP,etc) IP Layer IP Signalling (SIP,etc) IP Layer Traffic, Flow QoS Management Traffic, Flow QoS Management Traffic, Flow QoS Management MPLS Signalling MPLS Signalling MPLS Signalling WDM Management WDM Management WDM Management RWA Signalling RWA Signalling RWA Signalling Optical Link Management Optical Link Management Optical Link Management Core Router Edge Router Edge Router

14. IP/MPLS Router IP/MPLS Router Optical Edge Router Optical Edge Router MPLS-Based Optical IP Network Architecture Customer Network IP/MPLS Network Customer Network IP/MPLS Router Optical MPS Sub-Network Optical Edge Router Optical Core Router Performs label merging/tunneling to optical lambda LSPs. Perform Explicit Routing on lightpath LSPs with optical switching fabrics LSPs within Electronic MPLS Clouds Note) LSP: Label Switched Path

15. IP/MPLS Router IP/MPLS Router Service Model for Optical Internet - 1Domain Service Model Server-Domain Optical Sub-network Control & Management Plane Client-Domain IP Network Client-Domain IP Network NNI Optical Node Controller NNI NNI UNI UNI (GMPLS signaling is not shown at Client) Signaling exchange Optical Edge Router Optical Core Router Loose Binding in Optical Path Data Transfer Optical Path User Plane Optical Node Optical Node Optical Node Note) UNI: User to Network Interface NNI: Network to Network Interface MPLS: Multi-Protocol Label Switching GMPLS: Generalized MPLS

16. Service Model for Optical Internet - 2 • Domain Services Model • Clients access to optical network using well defined UNI • Client/Server domain relationship • IP is a client of the optical domain • Optical layer provides point-to-point channels for clients • Optical/transport paths requested by clients and setup dynamically within optical network. Path setup method unspecified • For router network clients, optical paths are used as point-to-point IP links • For TDM clients, optical paths are large structured, fixed bandwidth paths

17. IP/MPLS Router IP/MPLS Router Service Model for Optical Internet - 3Unified Service Model Optical Sub-network for Control Plane Control & Management Plane IP/MPLS Network IP/MPLS Network NNI UNI Optical Node Controller NNI NNI UNI Common Signaling based on GMPLS Optical Edge Router Optical Core Router Tight Binding in Optical LSP Optical LSP User Plane Data Transfer with label information Optical Node Optical Node Optical Node Note) UNI: User to Network Interface NNI: Network to Network Interface MPLS: Multi-Protocol Label Switching GMPLS: Generalized MPLS LSP: Label Switched Path Optical Sub-network

18. Service Model for Optical Internet - 4 • Unified Service Model • A single control plane for User and Optical Network Node • single signaling and routing protocol • MPS-based optical network using label binding by Clients • IP router’s FEC is matching to Optical LSP • IP signaling and routing protocols need to be modified to support optical characteristics • No UNI, Client use NNI directly

19. Network Architecture Model • Overlay Model • Separate routing of IP and Optical layer • Separate the control plane between Optical Transport Network (OTN) domains and IP domains • Augmented routing can be applied • Peer Model • Integrated signaling and routing of IP layer and Optical layer • Same control plane in the OTN and IP domains

20. IP/MPLS Router NNI NNI Overlay Model Core IP/MPLS Network IP/MPLS Router IP/MPLS Router IP/MPLS Router Customer IP/MPLS Network UNI or Proprietary UNI or Proprietary Optical C-/M-plane for Signaling & Routing Optical U-Plane for Data Transfer Signaling exchange UNI OXC NNI OXC Optical Cross-Connect (OXC) Data Transfer OXC Optical Sub-network

21. IP/MPLS Router IP/MPLS Router NNI Peer/Integrated Model Optical C-/M-Plane for Signaling & Routing Optical U-Plane for Data Transfer Single IP layer driven control plane for both IP and optical layer Customer IP/MPLS Network Control-/M- Interface Signaling exchange UNI (GMPLS - modified IP signaling/ routing protocols) Optical Switched Router OSR U-Interface Data Transfer Optical Switched Router (OSR) OSR Optical Sub-network OXC : Optical Cross Connect

22. Management Infrastructure • MPLS MIBs already exist for • Modeling the cross-connects in an LSR • Requesting and controlling TE-LSPs • Enhancements are being made to • Support wider definition of “label” • Allow control of new GMPLS features • Other new MIBs for • LMP • Link bundling

23. Reliability Requirements • Problems • Layer 3 rerouting may be too slow • Granularity of lower layers may be able to protect traffic may be too coarse for traffic that is switched • Lower layers may provide link protection • But is unable to provide protection against node failures or compute disjoint paths  Need for GMPLS- based recovery • Establishing interoperability of protection mechanismsbetween GMPLS enabled devices (Routers, SONETADMs, Optical Cross- connects, etc) • Enables IP traffic to be put directly over WDM opticalchannels and provide a recovery option without anintervening SONET layer.

24. Restoration Requirements • Restoration Time under 50 ms • Required Steps • Fault detection, Fault isolation, Error reporting, Re-provisioning, Switch-over • Controlling Management Status • Management status carried on Signaling requests and responses, Notify messages • Alarm-free setup and teardown • Status control during protection switchover

25. Traffic Engineering Requirements • Require to compute paths to deliver QoS • Need to know basic topology of the network • Need to know available resources on links • Must also know link properties in network • User/application requests services

26. Managing Optical Link Resources • Need to address a common set of issues • Isolation of faults transparent networks • Scale the number of links without increasing configuration • Scale the parallel (“bundled”) links without increasing the amount of information • Requires a new protocol to resolve these issues

27. Link Management Protocol • Control Channel Management • Maintain an IP control channel between LMP peers • Link Verification • Map interface IDs and verify data connectivity • Link Property Correlation • Discover and agree data link properties • Fault Management • Detect and isolate faults • ! Authentication

28. MPLS Benefits for Optical Internet • MPLS was initially designed to optimize and scale IP core networks, via traffic engineering • Core for aggregation and scalability • Edge traffic classification • Take advantage of these existing MPLS capabilities • Use label stacking for hierarchical aggregation • Provides scalable edge services

29. MPLS-based Control for Optical Internet – 1 • IP-based approaches for rapid provisioning • Re-use existing signaling framework • Less standardization, faster vendor interoperability • No addressing concerns arise (use IP addresses) • Key MPLS features exploited • Hierarchical LSP tunneling (label stacking/swapping) • Explicit routing capabilities • LSP survivability capabilities • Constraint-based routing

30. MPLS-based Control for Optical Internet – 2 • Traffic Engineering in Optical Network • Optical network load balancing • Performance optimization • Resource utilization optimization • Extensions to MPLS signaling • Encompass time-division (e.g. SONET ADMs), wavelength (optical lambdas) and spatial switching (e.g. incoming port or fiber to outgoing port or fiber) • Label is encoded as a time slot, wavelength, or a position in the physical space • Bandwidth allocation performed in discrete units.

31. MPLS-based Control for Optical Internet – 3 • Supports Multiple Types of Switching • Support for TDM, lambda, and fiber (port) switching • OXC (Optical Cross-Connect) can switch an optical data stream on an input port to a output port • A control-plane processor that implements signaling and routing protocol • Optical Mesh Sub-Network • A net. of OXCs that supports end-to-end networking • Provide functionality like routing, monitoring, grooming and protection and restoration of optical channels

32. PSC TDM LSC FSC Forwarding Interface of GMPLS • Packet-Switch Capable (PSC) • Recognize packet/cell boundaries and forward data based on header. • Time-Division Multiplex Capable (TDM) • Forward data based on the data’s time slot in a repeating cycle. • Lambda Switch Capable (LSC) • Forward data based on the wavelength • Fiber-Switch Capable (FSC) • Forward data based on a position of the data in the real physical spaces. Allow the system to scale by building a forwarding Hierarchy

33. Technical Challenges • Scalability • Quality of Service • Needed for existing user applications to work as expected • Service Transparency • For user applications to work • Manageability • Provisioning

34. Conclusions • Architectural Evolution for Optical Network • Boundary between Control Plane and Management Plane is obscure • Single Control/Management Plane both for IP domain and Optical Domain • IP-centric control mechanisms has cost competitiveness • Extends MPLS to Optical World • Extends Generalized MPLS technologies to encompass time-division, wavelength and spatial switching network • Adapt IP Traffics to Optical Bandwidth Granularity • Generalized MPLS is used for network evolution scenario