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

[Matthias Apitz]

El día Tuesday, January 17, 2012 a las 08:08:48PM +0100, Matthias Apitz escribió:

> 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;

the above (only upstream RTP) looks like this in TCPDUMP:

13:32:40.345152 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.366523 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.387812 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.398505 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.419845 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.441164 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.462554 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.483815 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172
13:32:40.505161 IP 10.59.47.201.1028 > 86.64.162.35.12978: UDP, length 172

no UDP from 86.64.162.35 (ekiga.net) is coming through while connected
via O2 UMTS network;

I've borrowed another SIM card from Vodafone.de and with this it looks
better like this:

12:07:42.541558 IP 86.64.162.35.11108 > 127.0.0.1.1024: UDP, length 172
12:07:42.549452 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
12:07:42.551554 IP 86.64.162.35.11108 > 127.0.0.1.1024: UDP, length 172
12:07:42.570774 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
12:07:42.572426 IP 86.64.162.35.11108 > 127.0.0.1.1024: UDP, length 172
12:07:42.592137 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
12:07:42.592243 IP 86.64.162.35.11108 > 127.0.0.1.1024: UDP, length 172
12:07:42.611989 IP 86.64.162.35.11108 > 127.0.0.1.1024: UDP, length 172
12:07:42.613485 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
12:07:42.634805 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
12:07:42.656108 IP 109.43.97.247.1024 > 86.64.162.35.11108: UDP, length 172
...

i.e. there is coming RTP traffic down with destination 127.0.0.1
(localhost); but the SIP client 'baresip' does not see this; in
'baresip' only the outbound bit/s shows some value ~64255 bit/s,
while the inbound stucks with zero;

any idea?

Thanks

	matthias

-- 
Matthias Apitz
e <guru at unixarea.de> - w http://www.unixarea.de/
UNIX since V7 on PDP-11, UNIX on mainframe since ESER 1055 (IBM /370)
UNIX on x86 since SVR4.2 UnixWare 2.1.2, FreeBSD since 2.2.5