Thursday, December 18, 2008

Adventures in VOIP Part 1

In the interest of trying to avoid overload, This has been broken up over a couple of days. Read on, and I look forward to your commentary.

Hello again, it's time for another infrequent post by Jim the Windows admin. Since about Thanksgiving, here at our shop we have been getting a crash course in VOIP setup. Our current setup is an old Executone system that has been a work horse here at the shop for at least 8 years before I even got here. Unfortunately, like all old horses, it needs to be put out to pasture. We initially looked at going to VOIP almost a year ago, and to paraphrase the CFO "Limp the current system as long as possible". So of course when November rolls around and the system is restarting itself and dumping all calls 4-5 times a day, we suddenly have funding for a VOIP setup. Go figure. So luckily for us, we have a server we just freed up and our adventures with Asterisk can begin!

The project kicked off with the boss installing CentOS 5.0 and Elastix on a newly spare server. The last 3 weeks have been spent with the 3 man IT department here testing various phones and trying to emulate our current functionality in the new system as closely to the original as possible. For the most part the process hasn't been too bad. We've made a couple of rookie mistakes here and there, but we have a mostly operation system here. Here are a few things I've discovered while working on the system.


With the rushed time table we were handed, we have looked at 4 different brands of phones for use here in the shop. We looked at the Linksys SPA942, a PolyCom SoundPoint IP 330, a Polycom SoundPoint IP 430, a Cisco 7941 and a little later an Aastra 480i (make a note of this model number, it will come into play later). The dead simplest to set up (and the one the brass here liked the most) was the Linksys SPA942. If you don't need to do a firmware upgrade, you can go from box to working in about 5 minutes, which we in IT thoroughly enjoyed. Of course, after using the phone a bit more, we found that it is not as configurable as some of the other phones on the market (say the Aastra for example) but is perfectly serviceable for what we need. Not to mention it doesn't require text files to do configuration like the Polycom and Aastra phones. As for the Cisco, I'm not sure if we ever got it working. The boss said he would get to it, and I never felt like dealing with it. Sometimes it is good to be the underling.

After doing a little playing around with the setup on the Linksys, we decided to try out its functionality with POE and connecting the phone inline with the between the computer and the wall. To do this, we used a Dell Powerconnect 3448p to provide the POE and we also configured a VLAN for the phones. All was well, up until I decided to change something on one of the phones and my internet connection dropped. Apparently, when the phone reboots (which is does whenever you make a change on its web interface), the power is cut to its ethernet temporarily and you lose the packet forwarding through the phone. Granted it's only momentary, but suddenly dropping your SSH connection to the phone server is very annoying when you are editing a file.

The other thing I found during this process concerns our network map of the shop. The network map of the shop is old. And by old, I mean somewhere in the neighborhood of 6-8 years old. In that time, a new area in the shop was wired up and ports have been added in new places. And apparently no one bothered to label these new ports on the map. Proceed immediately to crawling under desks and trying to read someone's chicken scratch handwriting since they didn't bother with a label maker either. And to top it off, if the port was a low number (ie.6), you had to figure out if it was panel A or panel B. (Apparently starting the numbering where the first panel left off would have been too easy.) All said and done, flashing phones, installing them on desks, and moving ports around took about 3-4 hours and ate most of the Sunday after Thanksgiving day.

Remember that 480i I mentioned earlier? Well, my boss wanted to get a phone for our photo studio that would have multiple handsets since it is a rather large work area. And the 480i seemed to fit the bill. Of course he failed to notice one minor thing. Aastra has a 480i and a 480i CT. The two phones are completely identical in look function (and manual according to the site) excepting of course the ability to pair to a cordless handset. I am still waiting for the right phone to come in.