Re: [Ekiga-devel-list] STUN usage with SIP

[schwatzi web de]

Am 01.07.2015 um 11:43 schrieb Eugen Dedu:
> On 06/06/15 15:04, schwatzi web de wrote:
> > Hi,
>
> Sorry Scwatzi to answer so late, we are too busy.
>
> > How does STUN work in ekiga?
> >
> > STUN is normaly used as followed:
> > The STUN client should use the same socket as SIP and the received IP
> > and Port should then be used for constructing Contact- , Via- field and
> > SDP.
> > Then a keepalive is needed to keep the NAT Session in the router alive (
> > to refresh the mapping table entry).
> > This could be a done in many ways.
> > 1. sending registers more frequently
> > 2. sending empty SIP packets
> > 3. sending SIP Request like OPTIONS or NOTIFY(Event: keepalive).
> > A STUN Request should be done frequently in case the public address (IP
> > or port) changes( i.e. after a router restart )
> >
> > Looking at Ekiga
> > - it uses a different socket for SIP and STUN ( therefor it cannot use
> > the discovered port to build the contact SIP packets. So a user needs to
> > configure his router, too. i.e. Portforwarding or SIP-ALG)
> > - it adds the public IP in the contact but doesn't change the Via.
>
> Well, it does change the Via with the public address, see example below.
really ? what about contact uri and the contact in SDP
For my case (symatric NAT+SIP-ALG) ekiga does behave like i want it to.
In my specific case, ekiga writes port 5061(returned by stun) in the Uri 
but it really should be 5060.
is there a way to set the extern port manually ?

> > - it only sends one STUN Request when registering, and don't updates its
> > public address
> > - it has no keepalive
>
> It does have a keepalive (OPTIONS), for example:
>
> ... Housekeepe...baac34b700 SIP     Sending PDU (586 bytes) to: 
> rem=udp$86.64.162.35:5060,local=udp$82.238.108.175:5060,if=192.168.0.1%wlan0
> OPTIONS sip:ededu 86 64 162 35 SIP/2.0
> CSeq: 3 OPTIONS
> Via: SIP/2.0/UDP 
> 82.238.108.175:5060;branch=z9hG4bK9a00c7ec-a144-e211-80bf-0024d693d8e8;rport
> User-Agent: Ekiga/4.1.0
> From: "Eugen Dedu" 
> <sip:ededu 82 238 108 175>;tag=e6f5c6ec-a144-e211-80bf-0024d693d8e8
> Call-ID: 22a3bfec-a144-e211-80bf-0024d693d8e8 snoopy
> To: <sip:ededu 86 64 162 35>
> Accept: application/sdp, application/media_control+xml, 
> application/dtmf, application/dtmf-relay
> Allow: 
> INVITE,ACK,OPTIONS,BYE,CANCEL,SUBSCRIBE,NOTIFY,REFER,MESSAGE,INFO,PING,PRACK
> Expires: 3600
> Content-Length: 0
> Max-Forwards: 70
Also in my case ekiga does not send keepalives.
How can I force ekiga to do so ?
> The two other remarks are important, especially the first one!! 
> However, note that STUN is being dropped in ekiga, so this should no 
> longer apply for the next Ekiga release.
This is interesting. How will ekiga handle NAT in the future?
Personally I don't wanna miss it. Well, its usage in ekiga should to be 
enhance though.
(If you don't want to make the UI to complicated you could still provide 
some options which can only be set directly via gsettings (or whatever 
ekiga is using).
i.e. lot of phones have parameters you can only set when using 
provisioning. just some thoughts.)
If you come up with something different that works i think am fine with 
that, too.

> I put this on my TODO list also, if it will still be relevant.
Thank you for your effort. I really appreciate it. Ekiga is awsome