UDP nat question

Damjan gdamjan at mail.net.mk
Thu Apr 21 14:17:08 CEST 2005

> Imagine a host behind NAT with IP which has an application 
> on port 5060 ( a sip client) and opens a connection to a server outside 
> the NAT (the sip registrar with IP on port 5060), and 
> consider that the NAT box translates the SIP client src_ip to 
> and src_prt to 5054, for this communication.
> The SIP registrar is able to reach the SIP client running on 
> by using, but what about other 
> hosts on the Internet? Will they also be able to reach the SIP client 
> using the pair, 

They can't

> or only packets coming from the SIP registrar be accepted?


Sip clients behind NAT must use a Proxy.

damjan | дамјан
This is my jabber ID --> damjan at bagra.net.mk <-- not my mail address!!!

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