Voice over IP, for home office

(our scale of home office is probably sufficient for some small to medium companies as well)

Have (starting point)

• CyberGenie (now defunct company) phone system
  • 10 wireless handsets
  • Interferes with WiFI
• Three SBC POTS phone lines in 408 area code
  • Rollover between lines using simple "call forward busy" for 3 simultaneous lines
  • Only one phone number published
• Networking
  • House-wide WiFi with six access points (AP), 802.11 a/b/g
  • Gigabit backbone, 100MB to edges
  • Microwave, Cable modem, DSL connectivity

Want (more)

• Cheap, unlimited (no cost) calls to US, Finland and France
  • Local phone numbers in Finland and France for relatives
• Local area codes in Lake Tahoe, CA (+1 530) and Chicago, IL (+1 773)
• Multiple incoming and outgoing phone lines
• Intercom and internal phone system
• SIP style phone numbers: name@otala.com (substitute "name" with "taneli", and give me a holler if you have a SIP phone) as well as 11@otala.com
• Virtual extensions, with hard extensions
  • A virtual extension, such as 11@otala.com, will ring all phones (within my reach), then either go to voicemail or re-route to my cell phone
  • A hard extension, such as 100@otala.com, will ring my office phone, only, and will not route further
• Voice menus for routing calls, and communicating with home automation
• CDR (database, preferrably MySQL) of all call records
• Wired, Wireless (WiFi) and Speakerphones (CyberGenie only had wireless)
• Intelligent routing (for teenagers)
• Call forwarding (when not answered) to cell phones
• Voicemail (CyberGenie already had) with messages forwarding to email
• Integration to homebrew address/phone database (MySQL based), automatic calls

Solution (and then some)

• Asterisk PBX running on my server
  • Unlimited voicemail storage, number of extensions
• A couple of Sipura SPA-3000 Adapters
  • SPA-3000's allow me to still use a POTS line as a backup (for 911 & 411 calls, etc)
  • I can also use the CyberGenie? and normal phones as backups, during transition
• A residential BYOD VoIP account from Broadvoice
  • I'm not locked into any specific hardware or phones — my Asterisk server is all I need
  • Can't beat the price: $8.70/mth (tax included) for unlimited calling
• Soft phones (computer program) to turn every computer into a phone
  • I like x-lite from CounterPath, though... it's pretty, it works well, but its user interface is unusual
• eBay is a good place to find good "hard phones" (real phones)
  • For my (and my wifes) office a professional Polycom 500 speaker phone
  • For other places, a very nice Sipura SPA-841 wired phone (with speaker phone)
  • For WiFi, a few Zyxel P2000W v2 wireless phones (Interestingly, many of these come branded with a service, and it takes a little bit of effort to unlock them)
  • new Just received my first UTstarcom F1000 phone — cute, very cute... very old firmware (2.80st), but easily fixed by visiting Firmware web site which I found from this helpful FAQ
  • Application: Shared Address Book with Maps and Dialing implemented in MySQL database
  • Application: Wakeup Calls?

Still working on

• Adding a French and a Finnish VoIP provider
  • French is easy, FInnish seems to be complicated
  • UPDATE: Actually both French/Paris and Finland/Helsinki were quite easy, once I found Voxbone. Now I have a local phone in both locations, though the dial plan is starting to look like it needs a cleanup...
• Adding more phones
• Publishing all the configurations, dial plans, scripts, etc

Gotchas

• When obtaining "alternate numbers" Broadvoice issued a number that was already provisioned to someone else... my deepest apologies to the poor soul who got my 20 test calls — Important gotcha was that while VoIP calls to that number came right back to me (correct routing), the regular POTS calls went to the other subscribe — lesson is to test VoIP system with real phones
• There is some rare, random difficulty with the codecs (g.729 specifically), when dialing 800 numbers... easy solution is to divert the 800/888 calls via a POTS line using one of the SPA-3000 boxes — I set up a dial-plan where if you omit the area code, you override the call through a POTS line, nice extra feature
• For 911 and 411 calls, route the calls through POTS lines using the SPA-3000, so the fire department knows where to go
• ZyXEL P2000W v2 phones — really need the firmware upgrade — the 0003 firmware does not even work with Firefox, i.e. you have to use Internet Exploder until you're at 0005. But, once you're at 0005 things start to work beautifully. Word of caution — don't try to update more than one ZyXEL at a time with exploder as it will explode...
• ZyXEL P2000W v2, with a firmware of WV0001 — what a pain... the wireless encryption does not work at all! So, you temporarily take your wireless WEP encryption down, you restart the ZyXEL, you update immediately to the WV0005 firmware, put WEP encryption back on, and start configuring the phone. The WV0001 firmware is truly a joke.
• New phone numbers — did you forget to register them as "Do Not Call" with FCC/telemarketers... funny, so did I... Time to register all the new VoIP numbers with the Do Not Call list — remember it takes up to 3mths before the numbers are off the lists

Resources

Tips & Tricks

• Wake up calls — an extremely simple script, and you have wake up calls to any extension, with snooze and everything
• "Forget" to route any 900 calls — actually, just route them to busy signal... and nobody can do damage to the phone bill
• For the Zyxel phones; set up first profile (use create option once you have it configured) for your home WiFi, then set up additional profiles for roaming, if you have something like the WiFi-Free? in Sunnyvale
• Configure the WiFi phones to connect to your outside address of Asterisk, but set up a local iptables redirect on your boundary router, then set WiFi phones as Nat=yes (since the redirect will mess up the SIP registration address), and you have easy time roaming, as well as (almost) zero latency (echo) while inside your WiFi area
• While testing the system, you don't have to "sign over" your phone number right away, set up call forwarding from your old POTS number to your new VoIP number, until you are are satisfied (and the transfer goes through)

Files

Files for Address book are posted.
Continuing with more files:

• Firmware files/links to ZyXEL, Polycom, Sipura/Linksys
• Various scripts; Wakeup call (next gen), Virtual/extension scipts, phonebook, auto-provisioning

Security Concerns

SIP protocol does not contain much in the ways of security — on a technical level this is the way it should be, you can always add security by using appropriate firewalls, ipsec tunnels, etc. However, looking at the implementations, I see many cases where it would be trivial to hack into someone's PBX system and start using their lines (as an example).
Another example of a significant vulnerability is the way many VoIP phones are provisioned, it would be very easy to hijack phones or conversations if you are an insider.
I suspect, that VoIP spamming/stealing will become even bigger problem than email spamming, once VoIP becomes more prevalent and hackers start to concentrate on it.