[HacktionLab] Open Source / federated VOIP?

nmd nmd at riseup.net
Sun Jan 11 20:44:01 UTC 2015


 Hi, Thanks for everyone's suggestions and thoughts - I tried jitsi and was
semi-successful (got sound and video working in one direction and the
problems
may have been specific to one of the laptops). Might try that again in the
future but will also hope that these things get a bit simpler with time!
Cheers,
Nick

On 02/01/15 11:26, Tim Dobson wrote:
> On 31/12/14 16:24, johnc wrote:
> > Some Problems: -Mobile phone specific: -- mobile phones vary
> > greatly in their ability to run sip clients using crypto. I've seen
> > sip clients use 100%CPU with awful audio quality on a few phones
> > including high end samsung models. -- The latency on 3G is
> > typically around 1 second. Expect horrible lag etc. Using WiFi is
> > the only way to go unless you are lucky enough to be on 4G.
>
> > Non mobile phone specific: - ostel's only server is in the US,
> > latency is about 120ms. Not so good if you are in Europe. We could
> > build our own :-). - If you are going to build an ostel system I
> > suggest you include the topology hiding setup from my wiki or
> > elsewhere in your Kamailio config. SIP leaks IP/location
> > information unless you make an effort to obfuscate it.
>
> One solution I quite like, which works *if* you:
> a) trust the clients to a degree
> b) are happy with non-federated, centralised phone system, with the
> PBX as a single point of failure
>
> is:
>
> Your favourite SIP-based PBX system over OpenVPN.
>
> So, your phone connects to OpenVPN, and then the sip clients connects
> to the PBX via SIP, over a VPN.
>
> Pros:
> a) as secure as your deployment of OpenVPN
> b) removes NAT issues - there aren't any - the SIP/RTP goes via OpenVPN
> c) It mostly 'just works' (tested with .bg client connected to .uk
> server with no issues)
> d) possible on mobile [android], desktop and in modern Snom firmwares
>
> Cons:
> a) nontrival to setup
> b) centralised [not federated, and not designed to be]
> c) requires the giving out of VPN certificates to each client in advance
> d) SPOF [or compromise] on PBX system
> e) not really possible to 'just leave on' on mobile without emptying
> your battery
> f) only known to be *super reliable* on Snom desk phones, connected to
> an uncongested network
> g) certainly not without points of weakness
>
> ---
>
> It's not foolproof. It's not bombproof. But it is a nice architecture
> that works for some scenarios. :)
>
> -Tim
>
> _______________________________________________
> HacktionLab mailing list
> HacktionLab at lists.aktivix.org
> https://lists.aktivix.org/mailman/listinfo/hacktionlab


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.aktivix.org/pipermail/hacktionlab/attachments/20150111/76f0678b/attachment.html>


More information about the HacktionLab mailing list