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Building a Personal VoIP System

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Re: Building a Personal VoIP System

#52
post #38

People still actually make phone calls? I mean its neat that you can run your own voip, but I struggle to imagine it getting used much or being worth even $5/month

Yes, there are many people for whom voice phone is the preferred method of contact, and I accommodate them because they're important to me.

Re: Building a Personal VoIP System

#53
I am one of the few people from my generation to maintain a "land line" (VoIP) and I, too, run it with Asterisk and the FreePBX configuration GUI. FreePBX provides a ton of macros out-of-the-box so that adding unwanted callers to a blacklist or doing phone number lookups is simple, for example. Why bother? Well, I find it interesting and fun, but most of the stuff I like can also be done with Google Voice. So I don't recommend self-hosting a phone system unless you are really into the idea and want to spend a decent amount of time learning telecom domain knowledge.

Re: Building a Personal VoIP System

#55

One of my first job, in 201, was to create a spam faxing machine based on Asterisk. Once the initial setup was completed (T38 is a bit tricky to tune), it was very effective, it sent more than one milion of faxes every year.

Thank you for sharing your experience. How do you feel about it?

Re: Building a Personal VoIP System

#56
post #6

Cool to read someone indulge in this. For others interested with no prior context, also consider FreeSWITCH. Personal experience: I spent about 15 months working for a local telecom company, supporting their asterisk servers and developing interactive voice response applications. I was given the opportunity to build their residential voip service (in 2010?) from scratch and despite asterisk being so dominant I protot…

Asterisk dialplans can also be written in Lua, thanks to the Lua extension!

Re: Building a Personal VoIP System

#57

Ah good memories! Even though I knew nothing about VoIP I installed, years ago, one at my wife's little SME using "RasPBX" (a distro made of Raspbian + FreePBX + Asterisk) running on a... Raspberry Pi 1 (maybe a Pi 2 but I'm pretty sure it was a 1). The Pi was booting from the SD card but everything was running on an external HDD. I did put six Cisco VoIP phones and all was working fine as long as no more than four p…

I have a tangentially related problem I have been battling with that you may be able to help me with. I'm moving overseas (Australia to Denmark) and would like to keep my current mobile phone number working for calls and SMS , but use it from afar. I would be able to leave a raspberry pi at a friend's house. Can you use this setup without a SIP provider? Would you need to buy a modem for the raspberry pi?what would you do?

Re: Building a Personal VoIP System

#58

Excellent article, and sections "NAT Problems" and "NAT Solutions" are a good starter on that topic. Except even third-choice solution is not always feasible. Reserving fixed RTP/UDP port range is not possible with carrier-grade NAT, which is quite common with residential ISPs and nearly-universal with cell ISPs. Fourth-choice would be to reserve port range on a personal server (which would run B2BUA, asterisk in OP'…

One often sees the STUN, TURN or ICE protocols around SIP-based VoIP, I believed they were supposed to help solve those issues?

They don't always work...

The idea is if you send UDP packets to destination so arranged by middleman(STUN) or to a proxy so arranged by middleman(TURN) as an outgoing traffic, your Wi-Fi should be smart enough to set up a temporary NAT entry to allow responses to reach your $LOCAL_IP:$PORT. In reality, the Wi-Fi may have short memory or may be dying behind a refrigerator covered in dust and not able to handle all necessary combinations and ranges of addresses and ports, resulting in various partial failures such as one-way audio or missing participant in a group call.

Fifth-choice option is to just encapsulate everything into a VPN, preferably L2 VPN over HTTPS to a server on a global IP. If it isn't working, there must be no Internet.

Re: Building a Personal VoIP System

#59
So, maybe one of the VoIP experts that showed up on this thread can help me with one doubt...

Let's say that I have a LDAP server where I manage user accounts, and I want people to be able to call each other with any SIP-enabled phone. I am not interested in voicemail/IVRs/any type of "voice application" on top of that. Do I really need Asterisk/FreeSWITCH or can I just go buy by setting up something like Kamailio?

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