Cone vs. Symmetric NAT
Cone vs. Symmetric NAT
| (a) Cone NAT | (b) Symmetric NAT |
Slide Notes
Saikat Guha, Yutaka Takeda, and Paul Francis, “NUTSS: A SIP based Approach to UDP and TCP Network Connectivity”, In Proceedings of SIGCOMM04 Workshops, Portland, OR, Aug. 2004, pages 4348 https://www.guha.cc/saikat/files/papers/nutss.pdf Links to an external site.
Transcript
[slide370] And if we look at what it basically means, is our host is back here, it has a private address, on the other side of the NAT we have some sort of public address, we can go to a STUN server, and now we can find out what our address is, and we can find the mappings of which port numbers to be used. That's fine if we have a cone NAT. If we have a symmetric NAT, what we actually get here is we can go to our STUN server, we find our IPv4 public address, but if we go to a different host, oops, we can get a different public address. So STUN won't help us in this case.