[Telepathy] telepathy-sofiasip parameters

[mikhail.zabaluev at nokia.com]

Hi,

> -----Original Message-----
> From: ext Florian Reinhard [mailto:florian.reinhard at googlemail.com]
> Sent: Saturday, January 29, 2011 5:57 PM
> To: telepathy at lists.freedesktop.org
> Cc: Zabaluev Mikhail (Nokia-MS/Helsinki)
> Subject: telepathy-sofiasip parameters
> 
> I'm working on a telepathy-accounts-kcm plugin for telepathy-sofiasip
> and the
> in-code documentation of the provided configuration parameters are not
> sufficient for me to be able to produce a sane configuration UI.
> Therefore
> some questions concerning telepathy-sofiasip's parameters:
> 
> discover-stun, stun-server, stun-port:
> In the code i found that discover-stun is ignored if stun-server is
> set,
> therefore if a user sets discover-stun to TRUE stun-server needs to be
> empty
> to make this configuration work?

Yes, as a parameter passed to the CM it should be empty.
I think now that it is inconvenient to a plugin implementation that would not want to lose the server name value even if discovery is enabled. Can you file a bug about it? Do you want this fixed in telepathy-sofiasip 0.6?

> local-ip-address / local-port:
> what are these used for, are they overriden by anything, does discover-
> binding
> affect this?

These affect the socket binding of the SIP UA. It's a way to ensure that Sofia-SIP uses a particular local IP binding on multi-homed hosts, something that it does not do in a satisfactory way automatically.
These should not be exposed in account configuration, and are provided for various automatic tweaks.

> proxy-host / port / transport:
> does proxy-host need to have the format "sip:<FQDN/IP>"?

No, it's supposed to be a FQDN or an IP address only.

> is transport really related to the proxy?

This will be the transport used to contact the proxy, so yes.
I think it also goes into the pre-set Route header for initial requests, if "loose-routing" is enabled. The route URI is mainly composed from the three parameters above.

> extra-auth-user / extra-auth-password:
> what are extra authentication challenges?

This is almost obsolete now that we have authentication channels.
We only need to implement digest authentication on demand in telepathy-sofiasip to make these parameters unnecessary.
Currently, these values are used in response to authentication challenges not belonging to the registration domain (as discovered from the REGISTER authentication).

> general:
> since i do not exactly know how sip NAT traversal works, i guess that
> stun,
> proxy and discover-binding (which seems to make sofiasip use natify and
> rport)
> exclude another?

No, STUN settings are for media streams only. The UAC implementation in sofia-sip currently does not use STUN for NAT traversal; it relies on the rport RFC and has somewhat rusty and partial support for what was the SIP outbound draft (now RFC 5626). "discover-binding" enables registration binding updates based on external IP address reciprocated from the proxy using rport.
Proxy settings and "discover-binding" are orthogonal.

> Are Natify and rport being used if there is a STUN server?

Yes.

Looks like I need to spend some time documenting all these properties better.

Hope this helps,
  Mikhail