IP external paging with Asterisk

Aaron Rosenthal — Thu, 26 Jun 2008 23:35:28 +0000

In the spirit of exploring the capabilities of Asterisk beyond its typical use as an IP PBX, external paging is a great feature to increase the value of your Asterisk system by having it assume the functionality typically reserved for a distinctly separate system and additional investment. Most people configure Asterisk systems for paging via phones but when dedicated paging is required, and when the need to page must take priority over a voice call, then external speakers are the way to go. This is often the case for hospitals and schools.

Just the other day I had a meeting with a car service organization who needs a new IP PBX system. Unfortunately they had recently made a large investment in a brand new paging system and had to postpone their IP PBX investment. When I learned that this 50 seat organization spent $30K on a dedicated paging system I whacked the guy on the back of the head for stupidity and explained that they could have purchased a brand new IP PBX + Paging system for not much more.

So some of you might ask “what external paging speakers work with Asterisk?”. Well I’ve only found one company that builds a completely open IP/SIP paging speaker and that’s CyberData. They have a whole line of paging speakers including ceiling speakers, wall speakers, voice boxes, paging amplifiers, and more…. all of which come in POE and non-POE options. Although the hardware is a little more expensive than analog paging speakers (most range from $250-$350), the fact that they can be tied into an existing investment in Asterisk and that they operate over the same ethernet wiring already in place makes the TCO very compelling.

Other than CyberData, does anyone know of or have used other SIP paging speakers?

Get to know SIP if you haven’t already

Aaron Rosenthal — Thu, 26 Jun 2008 23:30:39 +0000

I still find it surprising the number of IT directors and CIO’s who still have no idea what SIP is. This is mostly the case with SMB businesses but even if you’re a small multi-site organization, you’re not doing anyone justice by ignoring new technologies. Because I run into so many people who don’t have a solid grasp of what SIP can do, I wanted to write a post laying out some examples.

So what is SIP? Only the greatest communications protocol in the world! Go wiki SIP for a technical overview but I’d like to discuss the benefits of SIP by using a simple example. Consultants and sales people don’t necessarily need to know how specifically SIP works but they should really understand what it could do for their clients. I find that people are less aware of SIP simply because carriers are slow to roll out their own solid SIP services since doing so can cannibalize some of their own business.

There are two primary methods for delivering SIP to a customer. The first is via the Internet and the other is via a dedicated circuit from the phone company. For a mid sized business I always recommend dedicated circuits because it’s the only way I can offer an SLA backed quality guarantee since there are far too many factors out of my control to guarantee voice quality over the Internet. This SIP example is a perfect demonstration of how SIP and MPLS can help dramatically improve the communications of a mid-sized organization with 3 locations.

I have a little medical center that operates 3 equally sized offices with approx. 50 employees at each site. Before we came into the picture, each site had its own independent legacy Avaya system connected to its own dedicated voice T1. Each site also had a dedicated data T1. Because the EMR system was located at the HQ site, each medical center was additionally connected to the main HQ via a point-to-point for application sharing. So in total this medical center was paying for 3 voice T1’s, 3 data T1’s, 2 point-to-points, and supporting 3 disparate analog Avaya systems. This setup is absolutely absurd from today’s standards but 8 years ago it would have been completely normal.

What was the solution? Simple as this: Replace all 3 Avaya systems with a single Asterisk system at HQ, deliver a 10meg MetroE to each of the 3 sites thus replacing all T1’s and point-to-points….and that’s it! By using SIP, we can route all voice traffic from the 2 sites through HQ then out to the PSTN. Data was dramatically increased from 1.5meg to 10meg and now all three sites can call one another for free while being able to transfer calls between sites, all the while having a fully meshed data network for their application sharing (made possible by MPLS). This is a HUGE improvement from the old setup… the best part being a projected savings of ~$4K/month which pays for the new phone system in 2.5 years.

Talk about a perfect client needing a complete communications overhaul. The encouraging part is that there are still thousands of businesses out there with the same horrible setup… we just have to find them and whip them into shape!

I recommend that you check out the SIP Forum to learn more about SIP and see what else other telecom professionals are doing.

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IP external paging with Asterisk

Get to know SIP if you haven’t already