PPP to UMTS provider && incoming traffic (TCP, UDP)

[Maciej Milewski]

Dnia wtorek, 17 stycznia 2012 20:08:48 Matthias Apitz pisze:
> Hello,
> 
> I'm used to connect my FreeBSD 10-CURRENT netbook to Internet via PPP;
> the provider in question is a German O2 UMTS provider; so far so good,
> i.e. all is working as it should: outbound HTTP, SSH, SMTP (I'm just
> sending this mail through such a connection), ...
> 
> what does not work is VoIP; the call is established via SIP (using a
> STUN server), but remote audio RTP packages are not coming down; I
> checked this with TCPDUMP: only upstream RTP is send, no incoming UDP;
I observed similar problem with L2TP VPN and for me it looks that they are 
blocking incoming/returning UDP traffic in public APN.
On the server side I see both incoming and outgoing traffic but device 
complains that it's unable to connect. If I switch to local wireless network 
then everthing works fine. I suspect that's because they are selling 
special(money) APNs.

> as well I checked incoming TCP, for example incoming SSH or HTTP; it
> seems that incoming UCP/TCP is just not coming through the PPP link;
> 
> before bother (complain) the provider with this, I wanted to ask if I
> miss something in the PPP configuration to get incoming delivered;
> 
> note: I'm not talking about NAT to some stations on a LAN, I just want
> get IP to the local host (interface tun6); as well I disabled ipf(8)
> which I have configured normaly;
> 
> any ideas? thanks in advance
> 
> 	matthias
--
Maciej Milewski