1. Digicom II Digital Communications Part II Based on book by Keshav “An Engineering Approach to Computer Networking” Jon Crowcroft http://www.cl.cam.ac.uk/~jac22

2. Any Questions?  …otherwise we can avoid all these 11am meetings  …otherwise we can avoid all these 11am meetings

3. DC-II (=DC-I++) :- Contents The Telephone Net (well its been around 100 years, so there must be some lessons in it) The Telephone Net (well its been around 100 years, so there must be some lessons in it) The Telephone Net (well its been around 100 years, so there must be some lessons in it) The Telephone Net (well its been around 100 years, so there must be some lessons in it) The Internet (about 25 years old, and looking decidedly shakey) The Internet (about 25 years old, and looking decidedly shakey) The Internet (about 25 years old, and looking decidedly shakey) The Internet (about 25 years old, and looking decidedly shakey) Asyncronous Transfer Mode (a failed, but bold attempt to mix Telepone and Internet) Asyncronous Transfer Mode (a failed, but bold attempt to mix Telepone and Internet) Asyncronous Transfer Mode (a failed, but bold attempt to mix Telepone and Internet) Asyncronous Transfer Mode (a failed, but bold attempt to mix Telepone and Internet) Classic Simplistic Model of Modular Functionality for Communications Classic Simplistic Model of Modular Functionality for Communications Classic Simplistic Model of Modular Functionality for Communications Classic Simplistic Model of Modular Functionality for Communications Some Systems Design Paradigms, often orthogonal to Layers Some Systems Design Paradigms, often orthogonal to Layers Some Systems Design Paradigms, often orthogonal to Layers Some Systems Design Paradigms, often orthogonal to Layers Naming and Addressing, i.e. who is where? Naming and Addressing, i.e. who is where? Naming and Addressing, i.e. who is where? Naming and Addressing, i.e. who is where? A List of common protocols - see if you can spot design patterns? A List of common protocols - see if you can spot design patterns? A List of common protocols - see if you can spot design patterns? A List of common protocols - see if you can spot design patterns? Some Mapping onto implementation for CS Some Mapping onto implementation for CS Some Mapping onto implementation for CS Some Mapping onto implementation for CS Routing - How many ways can we get from A to B? Routing - How many ways can we get from A to B? Routing - How many ways can we get from A to B? Routing - How many ways can we get from A to B? Error Control - what do we do when things go wrong? Error Control - what do we do when things go wrong? Error Control - what do we do when things go wrong? Error Control - what do we do when things go wrong? Flow Control - stemming the flood Flow Control - stemming the flood Flow Control - stemming the flood Flow Control - stemming the flood

4. DCII Contents continued… Shared Media Networks (Ether/Radio etc) - some special problems Shared Media Networks (Ether/Radio etc) - some special problems Shared Media Networks (Ether/Radio etc) - some special problems Shared Media Networks (Ether/Radio etc) - some special problems Switched Networks - What does a switch do and how? Switched Networks - What does a switch do and how? Switched Networks - What does a switch do and how? Switched Networks - What does a switch do and how? Integrated Service Packet Networks for IP Integrated Service Packet Networks for IP Integrated Service Packet Networks for IP Integrated Service Packet Networks for IP APIs to Quality of Service APIs to Quality of Service APIs to Quality of Service APIs to Quality of Service Scheduling and Queue Management Algorithms for packet forwarding Scheduling and Queue Management Algorithms for packet forwarding What about routing with QoS What about routing with QoS What about routing with QoS What about routing with QoS The Big Picture for manageing traffic The Big Picture for manageing traffic The Big Picture for manageing traffic The Big Picture for manageing traffic Economics, Policy and a little MPLS Economics, Policy and a little MPLS Economics, Policy and a little MPLS Economics, Policy and a little MPLS