Redirect port 80 to (remote squid) port 3128

[polhallen]

HI all,
I've a small lan:

dsl<–->pfsense<--->lan1-192.168.10.0/24
                                lan2-192.168.20.0/24

I've squid proxy on lan2 (ip192.168.20.250)

I done a correct redirect from "NAT" --> "PORT F."

interface : LAN1
dest port range HTTP
protocol : TCP
nat ip : 192.168.20.250
port : 3128

it works (I see logs on 192.168.20.250) but is very very […] slow :-/

squid on 192.168.20.250 from same network works ok

how to audit the problem?

thanks for help!