1. Lappeenranta University of Technology Valery Naumov Telecommunications Laboratory naoumov@lut.fi Tel: 05 621 3618 “Why Do We Need WDM Networks?”

2. Growth of Traffic If xDSL reaches same penetration as modems then network capacity will have to increase by 100s times

3. Internet Traffic is growing around 10% a month Data network volume will exceed voice in 2000-2001 By 2005 voice will be 1-5% of all traffic

4. IP Telephony could be VERY BIG Source: Analysis

5. If IP will be the dominant traffic then optimize network design for IP! Internet traffic is asymmetric Telecommunication system of today are designed to support symmetric voice traffics 1) 2)

6. WDM - Wavelength Division Multiplexing

7. Why Do We Need WDM? WDM combines multiple optical signals so that they can be amplified as a group and transported over a Each signal carried can be at a different rate (STM- 1/4/16 etc.) and in a different format (SDH, ATM, data, etc.) voice data video Frame Relay ATM SDH WDM single fiber.

8. Multi-layer Networks ITU-T Recommendation G.805 “Generic functional architecture of transport networks”: A transport network can be decomposed into a number of independent transport layer networks with a client/server association between adjacent layer networks.

9. Optical WAN 3 STM-16 Tx 1 STM-16 Rx Both sides of fiber ring used for IP traffic High Priority Traffic Cannot exceed 50% of bandwidth in case of fiber cut Low priority traffic that can be buffered or have packet loss in case of fiber cut Asymmetric Tx/Rx lambdas that can be dynamically altered OADM SDH Traditional SDH Restoral

10. Optical MAN Carrier Routers To Protection Fiber To Working Fiber Packet over SDH GigaPOP Router GigaBit Ethernet University A Router OADM Ethernet Local WDM Fiber Ring Provided by Cable Company or Telecom Operator Cambrian Box ATM University B Router OADM Central Office

11. WDM Network R&D  Common platform to provide network management, security and support for integrated traffic  Capacity usage and routing strategies  Designing survivable optical networks  Wavelength management to ensure QoS  Protection strategies for service differentiation  Development of the switchable WDM network must occur in a number of phases:  point-to-point one channel,  point-to-point multichannel with WDM,  network with fixed routing of WDM channels,  network with protection switching capabilities in the WDM domain, and finally  flexible network with switching functions for all channels in WDM crossconnects

12. Distributed Object-oriented Tool for Network Visualisation and Analysis (DOTNET)

13. EU COST 263 Project Quality of Future Internet Services  QoS characteristics end-to end delay, jitter, throughput, reliability  Network resources bandwidth, buffer capacity, processing power  Resource management state control, selection, reservation, scheduling and protection  Traffic engineering traffic differentiation, provision of different QoS levels Each layer network uses its own dedicated QoS provisioning mechanism that is optimised for its particular usage