For peer-to-peer application developers, Network Address Translators (NATs) are an obstacle. One of the biggest problems is that a developer cannot assume consistent behavior of all NAT implementations. There is now an effort underway to create a standard for consistent NAT behavior. The effort takes place within the IETF's BEHAVE working group.
In a recent Internet draft entitled Application Design Guidelines for Traversal of Network Address Translators, the authors talk about "BEHAVE-compliant NATs" and "BEHAVE-compliant applications." A BEHAVE-compliant NAT is one that behaves according to the emerging standard. A BEHAVE-compliant application is one that correctly operates when the participating peers are separated by BEHAVE-compliant NATs. There is no cooperation -- no protocol -- between a BEHAVE-compliant NAT and a BEHAVE-compliant application. It's just that the application makes certain assumptions about how the NAT operates.
Posted by Doug Sauder at February 27, 2005 07:30 AM