baresip (was Re: Ekiga && FreeBSD (for a future without Skype)

Gary Palmer gpalmer at
Mon Sep 3 20:55:02 UTC 2012

On Mon, Sep 03, 2012 at 09:28:14PM +0200, Matthias Apitz wrote:
> El d?a Monday, September 03, 2012 a las 08:15:54PM +0100, Chris Rees escribi?:
> > > substitute with this Skype, for example that my wife could phone me from
> > > home to my FreeBSD netbook connected via UMTS to Internet while sitting
> > > in the greens, in a beer garden; I could never manage this; SIP, in
> > > general, seems to be a mess, and my UMTS provider, in detail, does not
> > > NAT the incoming IP traffic to my netbook :-(
> > >
> > > the dream continues to have video and voice without Skype, ofc
> > 
> > Well, UMTS tends to strictly forbid any VOIP traffic anyway; they're
> > run by phone companies, so they don't want you doing that.
> My UMTS provider is, a German o2 label; and they do no forbid VOIP
> as I read, and there is no problem with Skype calls, for example. It is
> just not working, not even incoming SSH is NAT'ed to the ppp interface.

Skype does stuff standard SIP doesn't.  e.g. AFAIR skype can tunnel its
traffic over TCP/80 to take advantage of firewall holes for HTTP traffic.
SIP was designed for an IPv6 world where endpoints are direclty exposed to
the Internet.  You probably have to use a SIP proxy on an unfirewalled
public IP to handle your traffic.

( SIP sets up random ports on both end points to exchange voice traffic
  over.  Most firewalls don't sniff SIP traffic and so the inbound packets
  are dropped.  NAT and SIP really don't like each other too much )


More information about the freebsd-multimedia mailing list