[HOT] Using Wifi to make phone calls from mobiles using a router.

Thu Jan 11 19:54:24 UTC 2018

Calling a user at an ip address is purely a technical solution that may or
may not be useful in the field.  To make it work it needs a set of clear
instructions.  How do you load the two apps for a start without an internet
connection, yes it can be done bit it needs to be documented. Yes the ip
addresses come from the router and are normally dynamic but some routers
will set up static ip addresses.  Even if they don't the ip addresses
change very slowly.

I totally agree that skype etc is better and there are solutions that will
connect csip to the normal phone network.

However every other solution I've seen needs special hardware.  A DNS
server for example or it needs a connection to the internet.

There are some mesh network apps but they depend on a minimum version of
Android.

>From a network point of view directly connecting the phones is much
satisfactory than crossing a mesh network especially for voice.

In the ideal world you'd unpack a laptop that had both Astrix (VOIP phone
exchange) and an email server such as Dovecot / Postfix.  Then use the
gmail app to connect to the local email server.  However that type of
solution requires a level of expertise to set up and maintain.

If you have a large area to cover then something like Commotion or
LibreMesh can be setup but they need special hardware.  Someone to set them
up and do a certain amount of maintenance.

For a small area and limited number of people and when no Internet or
special hardware is available then I think csip simple is worthy of
consideration.

Cheerio John

On 11 January 2018 at 12:42, Philippe Verdy <verdy_p at wanadoo.fr> wrote:

> There's no mistery to cross a router, most apps use UPnP in their local
> app to configure and keep open a routable port on the NAT router. Other
> solutions have existed but now UPnP is almost uniersally supported by most
> routers and users don't have to know their IP. Instead they renew their
> subscription (as long as their local app is running and connected to the
> Internet) to a directory server that will give routing info, and notably
> the public IP and port number to use to reach a user behind a NAT. However
> this is known to not work properly with some ISP's using "large NAT"
> (notably for mobile users: mobile users are instructed by their FAI to use
> their own telephony or VoIP service instead and pay their communications,
> and other people will call them to their normal mobile phone number!)
>
> So no it is not simple to make any direct peer-to-peer communication
> without some third party service and specific configurations. An IP is no
> longer sufficient (and many users now no longer have an IPv4, they are only
> reachable via IPv6, and many IPv4-only users can't reach these IPv6 users
> directly without a third party proxy).
>
> Direct peer-to-peer communication will be possible for every one if every
> one has an native IPv6 access (where NAT will no longer be needed: NAT over
> IPv6 is devil, only a transitory solutions for those users that still have
> only IPv4 connectivity and need to configure an external IPv6 proxy server
> providing them a single IPv6 address instead of a block of size /48 at
> least, where autoconfiguration allows setting a "permanently" routable IPv6
> addesses for each app without using any NAT). So to perform a call in IPv6,
> just can just connect to "[::<IPv6 address>]:<standard port for VoIP app>]"
> and you no longer have to do any port number translations or configuration.
>
>
>
> 2018-01-11 12:12 GMT+01:00 Bjoern Hassler <bjohas+mw at gmail.com>:
>
>> Hi John, Hi Philippe,
>>
>> Thanks for the post. I'd written this reply before Philippe posted, but
>> not hit sent, sorry. Let me send it anyway.
>>
>> To explain further: Unless one router extends the network of the other,
>> each phone would be behind a firewall created by the router. So you'd have
>> to place the phone in the DMZ or port-forward on the router. Using
>> https://en.wikipedia.org/wiki/CSipSimple might be especially helpful if
>> you are doing point-to-point WiFi (without internet connection of either
>> router). A "192.168.x.x" is network internal, so you won't be able to
>> connect between "192.168.y.y". And even then, as Philippe points out, the
>> address of the router may not be fixed.
>>
>> However, if the routers are connected to the internet, it would also be
>> possible to use commercial VOIP apps (like WhatsApp, Hangouts, Skype). I am
>> not sure how they route voice traffic these days, but Skype used to allow
>> peer-to-peer, which like Hangouts/WhatsApp should mean "peer-to-peer when
>> possible". In any case, for an app that just "handshakes" via the internet,
>> and then can use peer-to-peer, only the connectivity between the routers
>> matters. A nice feature would be if the app told you what it's doing (p2p
>> or via server) so that you know whether you're safe on WiFi or killing the
>> internet connection...
>>
>> There is an app called FireChat, that apparently can do p2p off-internet.
>> It's proprietary, and I haven't looking into it much. However, it strikes
>> me that such an app would be really useful, especially server-less, with
>> the option to connect to a global network if available.
>>
>> Is there anybody who wants to form a little action group to investigate?
>>
>> Hope this helps!
>> Bjoern
>>
>> On 10 January 2018 at 23:58, john whelan <jwhelan0112 at gmail.com> wrote:
>>
>>> The problem was mentioned some time ago in reference to a refugee camp
>>> in Europe.
>>>
>>> You need csip simple and to know the phone's ip address.  IP checker is
>>> a simple free app that will how this.
>>>
>>> "Just install csip simple and create a profile called "user", not
>>> linked to any server. To call another person with the same setup, you just
>>> need to know his ip address. Once they have sent it via voice, email, sms
>>> or whatsapp or ever (much better) a safer way like textsecure, you simply
>>> type "user at 15.14.173 et cetera (basically user@ other person's ip) and
>>> their Csipsimple will ring. It works and it's the purest form of Internet. "
>>>
>>> It doesn't have to be called user by the way.  So John or Mabel will
>>> work fine.  You do need the ip address so to call John it would be
>>> John at 192.168.2.99 mabel at 192.168.2.33
>>>
>>> You do not need the router to be connected to the internet for this to
>>> work by the way.
>>>
>>> Cut and paste should work.  So stick the wifi router up high and you
>>> should be able to cover a fair range.
>>>
>>> Cheerio John
>>>
>>>
>>>
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>>
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