In 1999, we replaced a paging console that used toggle switches to page and then talk to teachers in classrooms via talkback speakers. The original Stromberg-Carlson paging system was installed in 1956. In 1999, we removed the failing console and re-connected each speaker to a wafer that looped the speakers into one zone.
The analog amp connected to the previous 3Com NBX-100 IP-PBX provided paging capability: "All Call" (phones, external speakers, internal speakers), phones only, or PA only. Each had a unique three-digit dial code. The original paging system (controller) was failing and the speakers were old. As a note: IP phones are not a replacement for school paging, they are an adjunct.
We deployed a communications server under beta last year on a campus and reconnected the external PA system and assigned telephone extensions and the external pager to a paging group for All Call. Then we placed the extensions in another paging group by themselves and the external pager in another group by itself. Once we realized the SIP capabilities supported multiple paging zones, we sought SIP paging equipment that would work with the communications server.
Reusing existing analog paging at least in schools preserves investment in existing gear, minimizes disruption and avoids immediate cash outlay for a new system. In this particular case, the speakers are aging and there are areas that still need paging. The choices: do nothing, add paging to the existing analog system or add SIP paging by adding SIP-capable paging devices to the communications server and group those paging devices in user groups. Analog paging requires more installation time because the cable drops are home run to the amplifier. SIP paging devices require less installation time since their cable is connected to the nearest PoE LAN switch.
Our goal is to converge paging into the communications server and eliminate the analog paging system. Using the features of the communications server allows the customer to pay as they go, meaning they can purchase SIP endpoints and licenses as they can afford them, without completely abandoning the old PA system.
On average, we think we can deploy the paging in our schools for $18,500, and this does not include the cost of the communications server. Last summer after I explored the software capabilities of the communications server, I knew it was then time to work on finding a good fit for SIP endpoints for our schools' aging PA systems.
The communications server utilizes a solid-state hard drive with no moving parts. This is a key differentiator over other platforms utilizing a hard disk drive. There are 96 extension groups, and an extension may be a member of only one extension group. There are 8 paging groups and each paging group has up to 8 extension groups assigned to it. One extension group or external pager can belong to several paging groups. An external pager group is a single RCA mini-connection for an analog external paging system.
A SIP license for each SIP device is required. The endpoint that we adopted is the Algo 8180 SIP Audio Alerter from Algo Communications Solutions. There are two methods used to deploy the Algo device: use on alerter as the Master/Sender, and then set all other alerters as a Slave/Receiver (this requires only one SIP extension license and the multicast must not conflict); or set the multicast mode on all alerters to "none," and this means each alerter requires a SIP extension license to register with the SIP extension gateway. For simplicity, I will address the "none" setting, and in this example all alerters (SIP Paging Speakers) are individually registered and licensed. Each Algo alerter requires 12.95 watts for PoE when active and 1 watt when idle. Having enough PoE ports where you need them is just as important as having the power and backup (UPS) to support the PoE switches in every closet or IDF.
We set each alerter with an extension number in the 4xx range of the dial plan and placed the switch PoE ports serving each alerter into the "voice" VLAN. We enabled talkback and a "heartbeat light" feature that enables a blue indicator to flash every 30 seconds as visual confirmation of PoE power and SIP server registration. At night, at least in my office, that small blue LED is noticeable, and this may be a distraction in certain environments.
The 8180 devices have many cool features including logging, downloading the configuration files, customizing the wav files (audio sounds for alerting) and G.722 wideband paging unless you activate talkback; then you must disable G.722.
After installing the 8180 in a room on campus that hadn't had a working page speaker in years, we let the users experience the SIP paging and talkback feature. The room is typical of all classroom designs, with a separate room for lockers that students access upon arriving at or leaving the classroom. The 8180 automatically adjusts the audio output based upon the ambient noise measured just prior to the page alert sounding. We did testing of the audio volume setting of the 8180 and found that "6" worked best with the communications server.
Paging is dialable from anywhere unless you restrict your Automated Attendant and/or Dial Plan dial tables. We tested paging locally and from dialing into the SIP trunks, and then using paging codes. We also tested talkback capability. In all calls and all tests, all users could hear and be heard from anywhere within the classroom including the locker area with a wall separating the classroom space. Algo publishes a "coverage guide" found here.
While the communications server acts as the PBX, it also provides features and functionality of a paging server using Algo 8180 audio alerters. The cost to deploy IP paging is reasonable.
Now, with sound: remember that height and placement of the alerters (paging speakers) is relevant. The current limitation is that the 8180s are vertically mounted to a wall surface; Algo says they're working on a ceiling speaker that mounts horizontally to the ceiling grid. Algo also provides a discovery tool to find alerters on the network.
Converging gear on a campus is a worthy endeavor. Does it mean you still need an IP-PBX or communications server onsite? Not at all and that's the cool thing about IP. What convergence as a mindset can do specifically for the education vertical is provide a pathway to minimize the number of vendors by removing redundant systems and providing one common management platform: the network. Overall, the process requires a constant shuffling and re-evaluating until the right solution is achieved.
As an important endnote, we are asking ourselves: Can we drive costs down further? Maybe. We know with Algo alerters we can do provisioning using DHCP Option 66 or via a static server. There are three different ways to download provisioning files from a "provisioning server" using TFTP, FTP or HTTP. On larger installations, this can reduce setup time for the endpoints. Physical installation can be a challenge that adds labor, and of course depends on how well concealed the patch cord, jack and cabling is in each location. Less hardware means less cost, but more bandwidth adds to cost too, and then the dependency is upon bandwidth and the cloud provider.
Convergence isn't dead, it's simply a challenging process that may lead adopters down a path that they either abandon or pursue.
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