P2P and NAT

Firewall

The problem

Firewall

NAT

Why NAT is so popular

Simple NAT

Multiple NAT

NAT Mappings

Traversing a NAT that does not collaborate

Relaying

Connection reversal

TURN protocol

Role in TURN

NAT policies

UDP Hole Punching

Full cone

Full cone mapping and policy

Holes in Full Cone

Restricted cone

Restricted cone mapping and policy

Holes in Restricted Cone

Port restricted cone

Port restricted cone mapping and policy

Holes in Port restricted Cone

Symmetric NAT

Symmetric mapping and policy

Holes in Symmetric

STUN protocol

STUN protocol

TCP Hole Punching

TCP Hole punching

TCP Hole punching

TCP Hole punching

STUNT

Traversing a NAT that collaborates

Socks

SOCKS CONNECT

SOCKS BIND

SOCKS and Java

SOCKS4 and SOCKS5

UPnP NAT Traversal

UPnP API provided by COM

UPnP Port Forward

Issues with UPnP

References

References (2)