1. Next Generation Networks What’s New and What Isn’t John C. Bellamy Xalted Networks Inc.

2. Bellhead v. Nethead Circuit v. Packet Reliability v. Flexibility Line Protection v. Network Protection Hierarchical v. Flat Networking SONET v. Ethernet Conclusions

3. Integrated Voice Data v. Ethernet IVD Switch PSTN Mainframe/Server (Switched Access) PBX PSTN (Shared Access) Mainframe/Server Ethernet Twisted Pair Coax Circa 1985

4. AT&T v. Ethernet PSTN (Shared Access) Router Ethernet Switch PSTN (Switched Access) Router Twisted Pair Coax Circa 2001

5. Next Generation Digital Loop Carrier Remote Digital Terminal Local Digital Switch IDT TDM Digital Transmission

6. Hierarchical v. Flat Multiplexing a) Transport of PDH Multiplexed DS1 Signals in SONET STS-1 b) Transport of VT1.5 Mapped DS1 Signals in SONET STS-1 DS2 DS0 DS1 DS2... DS3 STS-1 DS0 DS1 DS0 DS1 DS0 DS1... STS-1 VT1.5 DS0 DS1... VT1.5 DS0 DS1... VT1.5 DS0 DS1... VT1.5 DS0 DS1... VT1.5 HH H Data c) Single Layer Multiplexing of Packet Switching

7. Complexity on the Edge PSTN Leased Circuits PSN RR Router (R)Store and Forward Packet Switching Node (PSN) Packetization Addressing Error Control Flow Control Reassembly Old Generation Data Network Circuit Emulation ES/R IP/ATM Core New Generation Voice Network RR Router (R)Store and Forward QoS Edge Switch/Router (ES/R) Adaptation Segmentation Speech Compression Voice Activity Detection Echo Control Reassembly Clock Recovery

8. Reliability v. Flexibility Tight Configuration Management Grade of Service Traffic Engineering Battery and Generator Power Back Up Line Powered 2500 Set Telephones Auto Discovery Best Effort UPS? Commercial Power CPE

9. Variable Length v. Fixed Length Addressing EOTOEO 10 Digit 7 Digit Dialing 4 Digit Dialing End Office Toll Office PSTN Dialing Plan (Circa 1995) RRRR IPv4 Addressing 32-bit Addresses Processed by All Routers

10. Fixed Length v. Variable Length Addressing EOTOEO 10 Digit Dialing 10 Digit Dialing End Office Toll Office PSTN Dialing Plan (Circa 2001) LSR MPLS Addressing Short Addresses (Tags) Processed by Label Switched Routers (Switches) LSR

11. SONET v. Ethernet ADMESADM ES Fast Ring Protection SwitchingSlow Network Layer Protection Switching ½ Capacity Dedicated to Protection Symmetrical Bandwidth Allocation No Bandwidth Reuse on Ring (UPSR) All Bandwidth Available with Discretionary Discard Unsymmetric Traffic Flows Supported Coarse Bandwidth Granularity Ethernet Switch Add/Drop Multiplexer

12. SONET v. Ethernet Augmentations Virtual Concatenation Generic Framing Protocol (GFP) Hybrid Data Transport Discretionary Traffic Quality of Service Resilient Packet Rings Ethernet over SONET SONETEthernet

13. Protocol Overlays SONET/SDH ATMFrame Relay IP ATM Physical Transmission Layer Ethernet IP

14. Conclusions Different Portions of the Network will have Different Solutions SONET will live A Nationwide Transparent Optical Backbone will not Happen