The UC520 Journey

On Friday I finally completed the cutover to our UC520, after running it in parallel for half the staff (2 phones on their desks) with our old Samsung DCS Compact II. Even better news, we are a week down the track and it’s still running. Yes of course I should expect that, but it is scary ripping all the trunks out of the Samsung. I’m going to share with you some of our journey towards the cutover, and some of the design decisions made. This system was installed in a small town in New Zealand, using VoIP over ADSL2+.

We settled on using 2talk as our VoIP provider, and so far, 98% of our outgoing calls have gone over that. A VIC2-4FXO card provides us with POTS trunks, just incase we run into internet connectivity problems. Users can dial 8 to force a call to go via the analog trunks, in case of a poor VoIP service. ISDN is too expensive as we are in a small town, and on a tight budget.

As well as the four internal FXS ports, we have a Linksys SPA8000 providing 8 extras. Still having some issues trying to send faxes over that, but we will get there. It is a shame the SPA8000 isn’t supported more by Cisco Configuration Assistant, but I’ve tried to put the less critical extensions onto the SPA8000.

We use a Snap ADSL2+ internet connection, and are using a Linksys AM300 in half bridge mode connected to the UC520 WAN port. All of our regular web browsing (and site to site VPN traffic) goes over a separate internet connection, independant of the UC520. I’ve got a spare AM300 in the rack should anything ever happen to it, all configured up and ready to swap over.

All of the voice equipment  & core network switches are connected to UPS battery backups, so in the event of a power cut (which happens fairly often) we can keep the phones up and running for about 40 minutes. The staff would have usually gone home if an outage lasted that long however, can’t do much with the computers down.

Surge protection on the analog trunks concerned me, we have been through quite a few trunk cards in the Samsung PBX, so we installed some APC phone surge protectors in the rack. They weren’t cheap, but we managed to squeeze 4 trunks through two of them (each of them protects 2 pairs, centre pair is line 1, next pair, line 2 etc). I made some breakout cables (cut a RJ11 modem cable in half and terminate the ends to a RJ45) to split the lines out to the FXO ports. Didn’t bother surge protecting the ADSL side of the lines for fear of reducing the ADSL performance. That’s what the spare modem is for!

I plan to purchase another VIC2-4FXO card to keep onsite as a spare should anything happen to the one in the device; they are much cheaper to buy from eBay than NZ new. That just leaves the risk of the UC520 itself failing; I hope the chances of this are very low because we can’t afford to have another one of those just sitting around. We will consider purchasing a SmartNET warranty contract, however it is a second hand device so have to work out what to do there.

The second hand system we got included a 7961 with a 7914 expansion module. Problem is we have two phone operators who need to see what is going on with the lines. Was about to fork out about $700 for another 7916/14 when I found the 7931.

Not quite as pretty as the 7916, but only cost us $290 and it provides all the functionality we require; will probably buy a few more.

The remainder of the phones are 7911s with a couple of 7941s. Our logo displays on the phone screens which is a nice touch.

If you would like to know more about any of this, don’t hesitate to contact me, I’d love to discuss it further.