UDP packets to PC behind NAT

[Janto Dreijer]

Steve Holden wrote:
> Note that TCP and UDP port spaces are disjoint, so there's no way for
> TCP and UDP to use "the same port" - they can, however, use the same
> port number. Basically the TCP and UDP spaces have nothing to do with
> each other.
>
> Most dynamic NAT gateways will respond to an outgoing UDP datagram by
> mapping the internal client's UDP port to a UDP port on the NAT
> gateway's external interface, and setting a converse mapping that will
> allow the server to respond, even though technically there isn't a
> "connection". The NAT table entries will typically be timed out after a
> short period of non-use.

So are you saying one can't use TCP to punch a hole for UDP?