[Computer Networking] {CMU14-740} Lecture 7: Peer to Peer Networking

 

The growth of peer to peer technologies has had a profound effect on the internet over the past decade. These systems have pioneered new media distribution mechanisms and in the process spawned legal battles and awakening of popular social movements. This class will examine the core technologies behind Napster, KaZaA, Gnutella, Skype and BitTorrent.

 

Query flooding in Gnutella networks

 

Lesson Objectives

By the end of this lesson, the student will be able to:

• list reasons that led to the creation of P2P networks.
• describe what an overlay network is and how it is different from the internet.
• use historical P2P networks to describe centralized P2P networks, fully distributed P2P networks, hierarchical P2P networks.
• describe search techniques in the various P2P forms, and to analyze search efficiencies.

Outline

• P2P Overview
• Architecture components
• P2P Case Studies
• Napster (Centralized)
• Gnutella (Distributed)
• BitTorrent
• Skype and KaZaA
• KaZaA reverse engineering study

Reading

• KR 2.5
• KaZaA Measurement [Liang2005]

Slides

• L07_P2P.pdf
• L07_P2P.pdf (No background version)

Due

• Paper Review: Liang2005
• Lab #0

Video

• Lecture Video

---

p2p ↑

non p2p ↓

 why p2p?

better performance, cheaper

 

 

left figure:

 overlay network is not internet

overlay network will pick up two peers, and say they are somehow neighbors

the architecture of overlay network will basically draw a straight line between one and another

and we will think that is just a single hop

so one node is next to another node in overaly network, there's maybe lots of hops going on.

how we choose the neighbors will be dependent on what's happening in the underlying network.

right figure:

p2p app adds one more layer on the top, and p2p application uses the overlay network.

 

---

https://wiki.p2pfoundation.net/Main_Page

---

 

 G is silent in pronunciation

 

fully anonymous => dont know who you are, but know IP address

 find friends => bootstrpping

 

 

a quesiton is what if there's a loop

 

 

3rd p2p network => solve the complexity of searching

 

SN - ON => connected by TCP, and the connection may across several routers and ISPs

 

 

https://www.wikiwand.com/en/Janus_Friis