network
data link
physical
application
transport
network
data link
physical
2.1Principles of Network Applications
1. Application architectures
Application architecture is distinctly different from the network architecture
network architecture: fixed
App architecture : how application is organized over various end systems
Typical application architecture
Client-Server (C/S)
Peer-to-Peer (P2P)
Hybrid of client-server and P2P
2.1Principles of Network Applications
Client-Server architecture
server:
always-on host
permanent, well-known IP address
server farms for scaling
clients:
communicate with server
may be intermittently connected
may have dynamic IP addresses
C/S apps:
Web, FTP, Telnet, e-mail
easy management
server is bottleneck
2.1Principles of Network Applications
Pure P2P architecture
no always on server at the center of apps
arbitrary end systems directly communicate
peers intermittently connected and can change IP addresses
example:
Gnutella
Highly scalable
But difficult to manage
2.1Principles of Network Applications

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