way to penetrate symmetric NAT

[Samuel Kevin <lo...@gmail.com>]

hi, all:
       i've fulfilled Cone NAT penetrating by using UDP pouching hole tech
in our P2P version prototype which we call PPclass. However, UDP pouching
hole can't work on symmetric NAT. Of course, you can still use udp pouching
hole tech by speculating the port one by one. It is low efficient and so far
as i know can't work most of the times.
      i reference the way Skype does.
http://www.mocaedu.com/mt/archives/000140.html, it seems they still choose
udp pouching hole tech to solve Cone NAT. As to Symmetric NAT, it seems they
use supernodes to forward the data.
      Actually, the current version of RealClass use the same
method--assistant DTU to forward data to clients under NAT. But if we want
to fulfill this feature in the next version of RealClass, the complexity of
the designing would be increased greatly.
     how i wish ipv6 could be deployed right now.......



-- 
Bowen Ma a.k.a Samuel Kevin @ Bluesky Dev Team    XJTU
Shaanxi Province Key Lab. of Satellite and Terrestrial Network Tech
http://incubator.apache.org/bluesky/