Re: [tlug] VoIP help

[Benjamin Kowarsch <trijezdci@example.com>]

On Oct 18, 2017, at 11:06, Kalin KOZHUHAROV <me.kalin@example.com> wrote:

The intention was to use it as a simple PBX with static SIP trunk,
provided by the ISP. So in ASCII, very simplified:

ISP --- router/fw --CAT6-- FritzBox :::DECT:::handset (x3)

Since changing provider is kind of impossible, I am left with 3 options:
1. Find a device that will replace the FritzBox, say up to EUR300
2. Add some kind of gateway/proxy that will register the FritzBox and
transparently pass all calls to and from provider and can run on cheap
hardware
3. Add inline "packet injector" to return "200 OK" to any REGISTER messages

As you might have guessed, I am eyeballing number 3, hopefully using a
tiny OpenWRT-based box. Also considering IP spoofing / direct
injection (since provider silently drops the REGISTER). Any thoughts?

Why on earth would you jump on a kludge as your first choice?

Better options would be ...

(1) replace that fritzbox with a solidly engineered open source IP-PBX solution:

https://freeswitch.org/

(a) use the fritzbox solely as DECT base station

(b) get a SIP driven DECT base station to hook up your DECT phones

[freeswitch]---SIP---[SIP/DECT basestation]---DECT---[DECT phone]

(c) replace the DECT phones with IP phones

(2) replace that fritzbox with a not so well engineered somewhat shaky but open source IP-PBX:

Asterisk

then use the Osmocom project's open source DECT stack to drive your DECT phones

http://dect.osmocom.org/

You can run any of this on a small embedded device like the ones from

http://www.pcengines.ch/

hope this helps

regards

benjamin