1. Distributed Peer-to-peer Name Resolution
Christian Huitema
Architect, Windows Networking
Microsoft Corporation

2. Vision: The user to user web!
Enable each PC to be a server
Serve ad-hoc groups
Promote and use IPv6, directly attach the users to the Net
Provide a server-less DNS for IPv6
Platform for developers
Mainframe PC
Web
P2P
Centralized
Personal
11/21/2018
Distributed Peer-to-peer Name Resolution

3. Making Windows a great platform for P2P
Firewall
Traversal
Sockets, DNS, files, print, ….
Firewall, NAT
Multicast?
IPv6
Security?
DNS?
Graphs
Group
Membership
P2P Names
11/21/2018
Distributed Peer-to-peer Name Resolution

4. Naming: the key to P2P development
Provide each computer with a name
Each computer is a server
Names must be stable
Resolve names to addresses
Also name groups, users…
Find a member of a group,
Find the location of a user
11/21/2018
Distributed Peer-to-peer Name Resolution

5. Peer-to-Peer Name Resolution
Identity = 128-bit number
No trademark!
Nodes manage a cache of “records”
Identity
IPv6 address
Proof (certificate)
Secure, Scalable, Robust, Private, Usable…
Look up initiated
11/21/2018
Distributed Peer-to-peer Name Resolution

6. Design Goal 1, Security: Names should resolve to the intended address,
One should not be able to fake an identifier
But one should not impose a central server…
Hello, I am
11/21/2018
Distributed Peer-to-peer Name Resolution

7. Secure: use certificates, prove the name
Record = Identity, IPv6 Address, Proof
Sign [identity, address] with local private key
Check signature before placing in cache
Host Identity = hash (public key)
Group member Id = hash (group key)
Group membership, certified by group key
Generic = hash (authority’s key, Name)
Validity certified by “authority”
11/21/2018
Distributed Peer-to-peer Name Resolution

8. Distributed Peer-to-peer Name Resolution
Design Goal 2: Scalable
1,000
Scale to the size of the Internet!
Assume at least one name per node.
Scale without a central server.
10,000
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
11/21/2018
Distributed Peer-to-peer Name Resolution

9. Scalable: a hierarchical cache
Circular space, centered on self
Cache levels:
First level: 360°
Second level: 36°
Etc.
Query:
Forward to “nearest”
Gain one level
log base X of (N) levels, 2.X Entries per level
11/21/2018
Distributed Peer-to-peer Name Resolution

10. Scalable cache management
Initial cache:
from memory, from neighbor
Proactive requests, “tell the network”
Update:
Learn from queries, requests
Try to fill each level, then replace
Finest level:
Learn about all “immediate neighbors”
11/21/2018
Distributed Peer-to-peer Name Resolution

11. Distributed Peer-to-peer Name Resolution
Design Goal 3: Robust
No central point of control, no central point of failure.
Large distributed system: some nodes will fail at any time.
Uncontrolled systems: some nodes may be actively conspiring against us … but hopefully not too many.
11/21/2018
Distributed Peer-to-peer Name Resolution

12. Robust: reputation & randomization
Neighbor reputation: from query completion + verification
Forward query: random choice, use reputation
Cache replacement: random & reputation
Timers, removal of failing entries from the cache
11/21/2018
Distributed Peer-to-peer Name Resolution

13. Distributed Peer-to-peer Name Resolution
Design Goal 4: Privacy
Some information is sensitive: location, membership in groups, documents…
Control who can learn what you publish!
11/21/2018
Distributed Peer-to-peer Name Resolution

14. Privacy: control the scope of publication
Peer-to-peer name cloud = set of caches
Parallel clouds
Ad hoc, on the same “link”
In the same “site”
Within a group (group = authority)
The whole Internet
Enforcement:
Check membership of requestor
Don’t forward outside of scope
Don’t cache out of scope records
11/21/2018
Distributed Peer-to-peer Name Resolution

15. Design Goal 5: immediately usable
On the Internet, Name = Domain Name
Used for Web Page, , FTP
Limited availability, requires a contract and a permanent IP address.
11/21/2018
Distributed Peer-to-peer Name Resolution

16. Usable: gateway to the DNS
Target Node: Reply on the same path
Global DNS name:
<ID>.pnrp.net
Use in URL,
Enables bootstrap
Central DNS gateway:
Publish NS record,
Join P2P cloud,
Forward requests
Local gateway:
P2P aware resolver
Look up initiated
PNRP.net
11/21/2018
Distributed Peer-to-peer Name Resolution

17. Peer-to-peer Naming: Summary
Target Node: Reply on the same path
Numbers are our friends: hosts, groups, URL
Scale to the size of the Internet, peer-to-peer, no server.
Prototype tested with 50,000 nodes
Secure, Private, Robust, Usable
Look up initiated
PNRP.net
11/21/2018
Distributed Peer-to-peer Name Resolution

18. Distributed Peer-to-peer Name Resolution
Peer-to-Peer Roadmap
UPnP Enabled NATs – End of ‘01
IPv6 Service Deployment – End of ‘01
P2P SDK Design Review – End of ‘01
P2P SDK beta – Q1-02
P2P SDK v1 – Q3-02
11/21/2018
Distributed Peer-to-peer Name Resolution

19. Distributed Peer-to-peer Name Resolution
Call to Action
Support IPv6 in your Applications
Leverage UPnP NAT Traversal Today
Participate in Software Design Review
11/21/2018
Distributed Peer-to-peer Name Resolution