1. 4/7/2019 7:12 AM
Peer-to-Peer and IPv6 Christian Huitema Architect, Windows Networking Microsoft Corporation

2. The Internet: a great tool to promote mainframes?
Hubert Curien, French Minister of Research, 1993:
Having a TCP-IP research network is great. Instead of funding a computer center in each university, we will only need a single large one in Paris.
This is not exactly the Internet we had in mind back then…

3. Enter NAPSTER, and peer-to-peer file sharing
Export the files in an appropriate folder
Announce the file in the central server
Search for interesting target
Retrieve the file in a peer-to-peer manner 1
export 4
download
Folder
Client
Client 2
announce
NAPSTER 3
search

4. Peer-to-peer is the basic design of the Internet
Recommended reading:
End-to-End Arguments in System Design.
Jerome H. Saltzer, David P. Reed, and David D. Clark.
But this seems to have been lost in the web…

5. End-to-end vs. Optimization
Short term problem
Connect many computers,
IP address are expensive
Short term optimization
Use a NAT box,
Hide many computers behind one address
Works well for web clients…
Today’s optimizations are tomorrow’s roadblocks !

6. Making NAPSTER work: global addresses
Server
Alice
Bob
Carroll

7. Making NAPSTER work with some firewalls and NAT.
Server
Alice
Bob
Carroll

8. In a world of NAT, NAPSTER cannot work!
Server
Alice
Bob
Carroll

9. Short term: hack the NAT…
Most NATs support some configuration procedure: “DMZ”, “service host”
We can automate this through UPnP
Discover the NAT
Reserve “port=xxxx” to “host=x.y.z.t”
Consequence for applications:
Use “parameterized” port
Read “port on this system” from a configuration file
Use “global address” in exchanges with peers.

10. In the medium term, we cannot program all NATs
Internet ? PC
API
NAT
NAT
home
ISP
By 2002, we will see ISP using layers of NAT.
In fact, they do that in China now…
We need IPv6 before that!

11. Address Shortage is Real!
Extrapolating the number of DNS registered addresses shows total exhaustion in But in practice, the “H-ratio” of log10(addresses)/bits reaches 0.26 in 2002.

12. 2002: the end of P2P?
As addresses get scarce, ISP can’t get enough allocation, more and more NATs get deployed, and peer-to-peer applications start to break!

13. We need IPv6, to change the Internet
Addresses are the key
Scarcity: the user is a “client”
Plethora: the user is a “peer”
IPv6 provide enough addressing
64+64 format: 1.8E+19 networks, units
assuming IPv4 efficiency: 1E+16 networks, 1 million networks per human
2 networks per sqft of Earth (20 per m2)
This enables peer-to-peer!

14. We can deploy IPv6 ! Applications update? PC-1 ICS Stack upgrade?
Use IPv6 for the new applications
Stack upgrade?
Available in W2K, Whistler (developers)
ISP waiting for Cisco?
“6to4” allows automatic deployment over v4
Supported by ICS (Whistler)
Natural evolution of NAT.
Single v4 IP
PC-2
PC-3
Advertise v6 prefix
PC-4

15. When can we get IPv6? 2000 Tech. Preview (W2K) 2001 2002
Developers (Whistler)
Deployment
Now!

16. More Information on IPv6
4/7/2019 7:12 AM
More Information on IPv6
Microsoft IPv6 white paper
Microsoft IPv6 Tech Preview News
Microsoft IPv6 Tech Preview Kit
Tpipv6 => technology preview IPv6

17. 4/7/2019 7:12 AM