Chapter 1: roadmap 1. 1 What is the internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and isps 1.6 delay loss in packet-switched networks 1. 7 Protocol layers, service models 1. 8 History Introduction 1-21
Introduction 1-21 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History
The Network Core O mesh of interconnected routers 口 the fundamental question: how is data transferred through net? m circuit switching: dedicated circuit per call: telephone net wn packet-switching: data sent thru net in discrete"chunks Introduction 1-22
Introduction 1-22 The Network Core q mesh of interconnected routers q the fundamental question: how is data transferred through net? m circuit switching: dedicated circuit per call: telephone net m packet-switching: data sent thru net in discrete “ chunks
Network Core: Circuit Switching End-end resources reserved for call u link bandwidth switch capacity o dedicated resources no sharin 口 circuit-|ike (guaranteed) 吵小 performance 口 call setup required Introduction 1-23
Introduction 1-23 Network Core: Circuit Switching End-end resources reserved for “ call” q link bandwidth, switch capacity q dedicated resources: no sharing q circuit-like (guaranteed) performance q call setup required
Network Core: Circuit Switching network resources a dividing link bandwidth (e.g, bandwidth) into pieces divided into"pieces" o frequency division a pieces allocated to calls o time division O resource piece idle if not used by owning call (no sharing) Introduction 1-24
Introduction 1-24 Network Core: Circuit Switching network resources (e.g., bandwidth) divided into “pieces” q pieces allocated to calls q resource piece idle if not used by owning call (no sharing) q dividing link bandwidth into “pieces” mfrequency division mtime division
Circuit Switching: TDMA and TDMA Example FDMA 4uses■口□口 frequency ------------------------ time TDMA frequency time Introduction 1-25
Introduction 1-25 Circuit Switching: TDMA and TDMA FDMA frequency time TDMA frequency time 4 users Example: