Paging – New Meet Old
Paging systems are one of those legacy IT components that often needs to live in the IP world.
"Legacy" is the word most used when talking about the many IT systems and wares of the past that won't die, paging among them. Paging remains a critical application in many environments, and so isn't likely to go away quietly -- and problems will crop up when trying to connect legacy paging systems to new IP communications solutions.
Network managers have a few options for resolving connectivity issues between legacy paging systems and new IP PBXes or other communications solutions. One approach is to connect the IP PBX to an analog terminal adapter or other device that provides an analog input (audio, telephony) to a paging amplifier. This will yield an "all call" paging solution, unless a dialer front-ends the adapter or is already a component of the legacy paging system and uses DTMF as input to target and then call specific paging zones (see a CyberData list of IP wares that support connections to analog paging amplifiers).
Another approach, as I discussed in a previous No Jitter post, involves using an IP PBX as the gateway and registering paging speakers as extensions.
No one size fits all, and each of these solutions has associated costs. Oftentimes, legacy paging gear remains intact for the simple reason that network administrators get snagged when attempting to change or eliminate this legacy gear.
The key considerations that come up when replacing legacy paging with an IP paging solution include:
- Cabling (audio cable vs. Cat5/Cat6) - I've previously advocated for preserving cabling infrastructure -- that's because I've installed cabling plant, and know the amount of effort required. Cable plant is valuable. Most old paging cabling is better than or as good as the cabling in use today. What is the business case to replace it?
- Endpoints - Do paging speakers require IP? Why?
- Integration - Does the project entail integrating new IP system and a legacy paging system? I believe most do, because I don't see key users (schools, hospitals, transportation, and warehouses) eliminating their paging systems unless they find significant cost differentials in doing so. Even then, are these verticals abandoning their legacy paging solutions?
Again, most paging challenges involve integrating a new communications solution (IP PBX, hosted, or UC solution) to a legacy paging system, and this involves some, but not all, components being IP.
When an IP paging application does replace a legacy paging solution then:
- Are the endpoints and other gear statically or automatically assigned, using Dynamic Host Configuration Protocol (DHCP), IP addresses? If DHCP, then what is providing the pool of IP addresses, and will the track record of that system or device hold up to support mission-critical paging?
- How will you secure the IP paging solution?
- How will you support access to the IP paging solution? If access requires Internet connectivity via the Web to the host and back again to the site, then how does this impact WAN traffic?
- Will paging traffic remain in its own virtual LAN? What other VLANs does paging need access to and from? Is remote paging a requirement?
- Do you have enough Power-over-Ethernet (PoE) ports and ample uninterruptible power supply capacity to back up the paging application if required? Do you have enough power in your closets to support additional need for PoE?
One of the key values of an all-IP paging solution is the ability to move and change the location of the speakers. In some industries this move, add, change, delete activity occurs frequently, while many paging systems once in place simply remain static.
Paging is sometimes critical, but "hardware – customer in aisle three" isn't one of them. On the other hand, a code red or code blue page in a hospital or on a campus is critical. The point is, paging can and should be looked at as an application but that application's value is specific to each organization.
How can UC improve paging? UC offers more choices, and can include paging. This is how discussions can begin before deciding to replace, integrate legacy gear, or eliminate paging.