用于rfc中的UDP的UNSAF方法4787

Question

我正在经历rfc 4787，作者提到了有关UNSAF方法。 什么是UNSAF方法？

Answer 1

正如selbie所说，UNSAF在RFC 3424中定义，意思是UNilateral Self-Fixing。

当客户端在NAT后面时，它不知道他的外部地址。根据这个RFC：

As a result of the nature of Network Address Translation (NAT) 
Middleboxes, communicating endpoints that are separated by one or 
more NATs do not know how to refer to themselves using addresses that 
are valid in the addressing realms of their (current and future) 
peers. Various proposals have been made for "UNilateral Self-Address 
Fixing (UNSAF)" processes. These are processes whereby some 
originating endpoint attempts to determine or fix the address (and 
port) by which it is known to another endpoint - e.g. to be able to 
use address data in the protocol exchange, or to advertise a public 
address from which it will receive connections.