IP in GPRS / UMTS networks

Most ISPs hand out IPs in the private Namespace (10.0.0.0)

Connection is being NAT'ed by the ISP

IP negotiation seems to be horribly broken with some ISP's, ppp(8) and pppd(8) have options to work around these things, use them

Compression built into the ppp protocol should be avoided, seemed to have negative effects on the speed, so turn it off

Depending on the connection type rtt times are ~ 200 ms

Often the ISP's are running weird proxy services