VoIP by The EggplantI spent several years working in telecom, at Winstar and for small vendors installing traditional hybrid PBX phone systems. I installed mainly Nortel systems, but we did service Avaya (Lucent), Toshiba, Panasonic and NEC on occasion. I originally installed a donated Nortel Norstar 824 with Startalk B Voicemail for the church back around 2000. Over the years we kept expanding it the system, but were limited by the two ports on the Startalk. I looked into upgrading the voicemail and it would be several thousand dollars and we would still be limited on features. The other issue with the Nortel is that programming was complex and it was limited and what it could do.

I began to look into newer hybrid PBX systems, but they were very pricey. At that time we had 8 analog lines and 20 phones, we were looking at $8,000 plus. Not only, was the initial cost high, but we would have to buy proprietary phones, and add expensive cards as we grow. It was around the same time that Asterisk started to gain traction. I played with it for over a year before I felt it was ready for production, my main concern was finding a good VoIP phone at a reasonable price. Late last year Linksys began to roll out good quality VoIP phones at a very reasonable price. Also, the release of Asterisk@Home, now called TrixBox, made installation and administration of Asterisk much easier.

We purchased 20 Linksys SPA-941 Two-Line VoIP Phones, a Polycom SoundStation IP 4000 VoIP Speaker Phone, and a Digium Wildcard TE205P Dual T1 card ( I would recommend getting the newer 207P because it comes with hardware echo cancellation) for less than $5,000 from VoIP Supply. I had an old Adit 600 channel bank sitting in my basement, remnants from my Winstar days, which turned out to be perfect for setting up an additional 24 analog extensions (hence the need for a dual T1 card). We had an extra Sony Vaio P4 2.8 HT 1 GB RAM and 120 GB Hard Disk that we installed the T1 card and setup Asterisk@Home 2.7 on. Ward Mundy over at Nerd Vittles has a great walk through: Newbie’s Guide to Asterisk@Home 2.7: Unabridged Installation and Upgrade Guide. The only thing we had to do different was the configuration for the T1 card and channel bank. We configured the VoIP phones one by one through their web interface, we are researching how to get the automatic provisioning via tftp working. Because our ISDN PRI wasn’t installed yet, we ran on VoIP trunks from Teliax until Cox cut us over.

To ensure good voice quality on the internal lan, we put all the VoIP phones on a separate VLAN, for those without managed switches, this could be accomplished by using a separate switch, isolated from your data network. Note, for those who have heard about sound quality issues with VoIP, this becomes a moot point when you can guarantee quality of service, such as on an internal LAN. The only potential for sound quality issues comes in when you are running calls over the Internet. For business quality service, I recommend routing service over the PSTN for now, with VoIP trunked over the Internet as a backup or secondary option (dial a prefix to route long distance calls over VoIP).

We have now been running the system for over two months on the ISDN PRI without any problems, thank God. We are enjoying the benefits of an enterprise class phone system, voicemail/fax to email, remote extensions and soft clients. We plan on adding at least 20 more phones this summer and setup paging so that school principal can call all the naughty kids to the office.

Recently, we also setup a smaller system for Coptic Orphans, they are running 10 Linksys SPA-941 VoIP phones and 4 analog lines using the Sangoma A200 PCI Card 4 FXO Ports + Echo Cancellation, costing just under $2000, not including the server (another Sony Vaio). This time we kept the fax outside the system to keep things simpler. Installation was fairly straightforward, make sure to follow the driver instructions on the Sangoma card closely, as that we got hung up when we missed one seemingly minor step.

Generally, ISDN PRI is used when you exceed 8 analog lines of service, it works out to be the same price or cheaper and you get the benefits of direct inward dialing (DID), caller ID, faster call setup, and 23 channels available for inbound/outbound calling. Upfront cost is a little higher due to the more expensive cards.

In the past couple months, Linksys had released more VoIP phone models which increase flexibility in planning out a system. If you are in the market for a new phone system, I would seriously consider a similar configuration.

VoIP PBX Links:
Trixbox – Latest version of Asterisk@Home.
Trixbox Asterisk-based PBX virtual machine
Asterisk Open Source PBX - Asterisk is the core PBX powering Trixbox.
Digium – Original Developers of Asterisk, they sell/support PSTN cards and an enterprise grade version of Asterisk.
Linksys – VoIP Phones and analog terminal adapters.
Nerd Vittles – Great guides on installing, configuring and tweaking Trixbox.
Voip Supply – We have been working with Brian Dooley, so far they have been great with us but I did see this post go up yesterday VoIPSupply.com disappoints, again.
Atacomm – Another VoIP equipment vendor.
VoIP Wiki – The best resource for all things VoIP, including driver configs for cards and sample setups.
Fonality – Preconfigured Asterisk VoIP servers, for those who don’t want to get their hands dirty.
Teliax – VoIP Trunking, they allow multiple simultaneous inbound and outbound calls on the same VoIP lines, but they do charge 2 cents a minute for incoming and outgoing traffic. Useful for testing and as a backup service provider.
CounterPath – X-Lite Free is a good soft client but you have to upgrade to transfer calls.
SJ Labs – SJphone is a full featured free soft phone for Windows