Alan Dix
Lancaster University and vfridge limited
Introduction
Structure
About Networks
Networks as Enablers: things that Are Only Possible with Networks
Remote Resources
People
Physical Things
Data
Computation
Applications
Networks as Mediators:Issues and Problems Because of Networks
Network Properties
Bandwidth and Compression
Latency and Start-up
Jitter and Buffering
Reliability and Loss, Datagram, and Connection-Based Services
Quality of Service and Reservation
Encryption, Authentication, and Digital Signatures
User Interface Properties
Network Transparency
Delays and Time
Coping Strategies
Timeliness of Feedback/Feedthrough, Pace
Race Conditions and Inconsistent Interface States
Awareness
Media Issues
Interactive Conversation and Action
Reliability
Sound and Vision
Compression
Jitter
Broadcast and Prerecorded Media
Public Perception: Ownership, Privacy, and Trust
Networks as Subjects: Understanding and Managing Networks
Network Models
Layers
Protocols
Internet Working and Tunneling
Routing
Addresses
All Together ...
Network Management
Network Awareness
Network Confusion
The Network Within
Networks as Platforms: Algorithms and Architectures for Distributed Interfaces
Accessing Shared Objects
Locking
Replication
Optimistic Concurrency for Synchronous Editing
Groupware Undo
Real Solutions?
Architectures for Networked Systems
Supporting Infrastructure
Awareness Servers
Notification Servers
Event/Messaging Systems
Resource Discovery
History, Futures, and Paradigm Shifts
History
Paradigm Shift
Futures (Near)
References
Figure 16.1:Copies of a web page in many places.
Figure 16.2:Bandwidth,latency,and jitter.
Figure 16.3a:No jitter, no problem.
Figure 16.3b:Jitter causes irregular reception.
Figure 16.4:Buffering smooths jitter, but adds delay..
Figure 16.5:Consistency breakdown.
Figure 16.6:The long path from PDA to web.
Figure 16.7:OSI seven layers and TCP/IP.
Figure 16.8:Protocol to send e-mail via SMTP.
Figure 16.9:Typical network packet format (simplified).
Figure 16.10:Internet protocol (IP) packet inside ethernet packet.
Figure 16.11:Routers send messages in the right direction through complex networks.
Figure 16.12a:Open-loop control.
Figure 16.12b:Closed-loop control.
Figure 16.13:Dynamic pointers from (Dix,1995).
Figure 16.14:Multiuser transformations.