pat does not preserve the original port number

[dhalevi]

hi,

I am using NAT with the overload option and I see this entry in the show ip nat translations,

Pro Inside global         Inside local             Outside local         Outside global

tcp x.x.x.x:80            192.168.1.1:60830    y.y.y.y:80             y.y.y.y:80

there are some other udp translations for the ip address 192.168.1.1 but none of them is using port 60830.

Why does PAT translate to x.x.x.x:80 and not x.x.x.x:60830 ?

thanks!