Legacy Alarming: Expanding Telecom Sites to Save Time and Money

Asentria Legacy Alarming

Although the use of smart IP or serial devices in telecom sites is on the rise, legacy alarms, such as contact closures or analog inputs, are still widely used in most sites. In many cases, these legacy alarms are gathered by old or obsolete equipment. There are significant costs to change out the older alarm methods for newer ones, limiting these old sites’ ability to implement new smart alarming or telecom site automation solutions.

Over years of working in telecom sites, Asentria has developed a wide range of solutions to allow the legacy alarms to be easily and quickly ported over to a SiteBoss unit. Whether 2G/3G sunset is forcing this change or 16 contact closures isn’t sufficient anymore, Asentria has a solution for porting over legacy alarms. Once these alarms are easily ported over to a SiteBoss, a whole new world of smart alarming, telemetry data, and telecom site automation is opened to the telecommunication site.

In addition to hardware to make porting over alarms quick and easy, Asentria has also worked hard to allow the SiteBoss to integrate into existing Network Management Systems (NMS). Often, this allows for the legacy alarms to be identical using the SiteBoss versus using the obsolete alarming system. This saves the cost of retraining Network Operations Center (NOC) personnel who do not have to be retrained when the SiteBoss is implemented at remote communication sites.

This document will go over some of the most common legacy alarming solutions that Asentria has implemented and show how Asentria has limited the labor, time, and cost of porting over legacy alarms to the SiteBoss.

Supporting Standard I/O Cards

Before discussing the custom legacy alarm solutions for the SiteBoss, we should touch on the standard I/O cards that the SiteBoss supports. These I/O cards come with 8 pairs of inputs that can be used for contact closures, analog voltage inputs, 4-20mA inputs, and relay outputs, depending on the card. These cards also have isolated and non-isolated input options. Currently, the SiteBoss has over 27 different I/O expansion cards, so the SiteBoss can be easily customized to have just the I/O needed. Since they are field swappable, the expansion cards also allow for the I/O to be expanded in the future without the need for a whole new SiteBoss unit.

Asentria I/O Cards
(Photo: Asentria I/O Expansion Card List)

These standard I/O cards have screw-down Phoenix terminals where alarms from various subsystems and sensors can be terminated. Using these cards may not give as much I/O as some of the other legacy alarming options discussed later in this guide. Since the cards slot into the SiteBoss unit when using these standard I/O cards, all alarms can be terminated at the 1RU SiteBoss, removing the need for additional space for a punch-down block.

Asentria I/O Card
(Photo: Asentria I/O Card without Phoenix Terminal)
asentria e8c expansion card
(Photo: Asentria 8C Expansion Card with Phoenix Terminal)

Custom Alarm Block

The most common way to port over legacy alarms that are wired to an existing alarm block is to simply put a new alarm block by the existing one and punch over the alarms. This solution takes far less labor than having to rerun alarms or dismantling an existing alarm block.

old alarm block to 32C8V8R alarm block
(Photo: Punching over from old alarm block to 32C8V8R alarm block)

Not only does Asentria’s custom alarm blocks make porting over existing alarms easy; it also adds I/O for new alarms. Unlike a standard 66 alarm block, which generally can handle up to 25 contact closures, Asentria’s custom alarm options all allow more I/O than that. Asentria’s custom alarm block comes in 32 contacts (32C), 64 contacts (64C) and 32 contacts, 8 analog inputs and 8 form-c relays (32C8V8R) varieties. With contact closure name, alarm state, trap number, class, and alarm alias all customizable field in the SiteBoss UI, alarms that are ported over to the SiteBoss can remain the same as far as the NOC or site technician is concerned.

Alarm Block Pin Out
(Photo: Alarm Block Pin Out)

Quickly Port Over Alarms with an Asentria 16C Expansion Card

Both Nokia and Ericsson Baseband Units (BBUs) can sometimes be configured to handle 16-32 contact closures using 4-8 CAT5 cables to wire these alarms to the BBU. When these BBU’s are replaced or upgraded, porting over these contact closures to some new destination can be a labor-intensive process. A site technician needs to cut open the CAT5 cables bringing the alarms to the BBU, and punch down the 16-32 wire pairs to an alarm block. When upgrading BBU’s across even a small network porting over alarms like that is a major cost in both money and time.

Asentria set out to create a solution to allow alarms from BBU’s to be ported over to the SiteBoss easily and quickly by coming up with a 16C expansion card. This expansion card has 4 RJ-45 ports and can handle 16 contacts each, and using two of these 16C cards allow for 32 contacts. Instead of needing to cut open the CAT5 cables carrying the alarms to the BBU, these CAT5 cables can be plugged directly into the 16C card.

Asentria Cards Cable and Alarms
(Photo: (A) Two 16C Cards Installed in SiteBoss, (B) Cable for 16C Card, (C) Alarms on Nokia BBU)

The 16C card also allows for a greater amount of contact closure alarms from a 1RU unit. As discussed in the section above, Asentria can easily accommodate 64 contact closures or more using alarm blocks. For some reason, like at a cabinet site where the room is scarce, where all the contacts need to be on the 1RU SiteBoss, the 16C card allows double the contacts compared to using our standard 8C card.

Customized Cable for Standard RJ-21 Alarm Block

While helping clients move over legacy alarming from old 2G equipment, Asentria came across several old BBU’s that have up to 25 contacts through a standard alarm block that connects to the old BBU via an RJ-21 connection. Replacing the old alarm block or even punching the alarm over to one of Asentria’s custom alarm blocks network-wide was determined to be too much labor. To help with this, Asentria set out to create a solution to allow the 25 old contact to be plugged directly into the SiteBoss, thus minimizing the cost of switching over the alarms.

To allow for the maximum amount of I/O, these Asentria high-density cards don’t have a standard alarm block pinout. Instead, the custom cable has a SCSI connection on the SiteBoss unit that breaks out into two RJ-21 connections. A custom cable was created for the equipment to allow for the Asentria high-density card to connect directly to a standard alarm block with an RJ-21 connection.

This custom cable still allows for the SCSI connection on the SiteBoss but only has one RJ-21 connection on the other end of the cable. This RJ-21 connection is a standard 25 pair pinout, so up to 25 contacts on a standard alarm block can be directly plugged into the SiteBoss. To not waste the other I/O, there are wire pairs for an additional 7 contact closures, 8 analog voltage inputs, and 8 form-c relays that can be punched down.

Integrating to an Existing Network Management Systems

Sometimes our clients want to upgrade their physical alarming device but was hesitant because they are happy with their NMS. The need to retrain NOC staff, rework ticketing workflow systems or update automated tasks can be a gating factor in the decision to implement a new site monitoring solution. To counter the problem, the SiteBoss is designed to easily integrate to legacy, or existing, NMS.

Unlike some monitoring devices, the SiteBoss is designed to work with many different NMS. If the NMS can capture SNMP traps or poll SNMP devices, the SiteBoss can likely work with it. Below is a list of just some of the NMS that the SiteBoss has been integrated to:

NMS Software Matrix List
(Photo: NMS Software Matrix List)

The SNMP traps that a SiteBoss sends are also highly customizable. The trap name, trap number, class, and alias all being customizable allows for the SiteBoss new alarms to mimic the alarms of the older legacy equipment. Once again, this is valuable because from the NOC the alarm looks this same. This allows old equipment to be taken out and a SiteBoss to be installed without changes being needed at the NOC level.


Even though smart alarming and telecom site automation is becoming more and more common, legacy alarming, such as contact closures or analog inputs, are still used at almost any monitored telecom site. The cost in money and labor to port over these legacy alarms to a new alarming device can be a gating factor in deciding to upgrade monitoring at a site. By providing a number of legacy alarming solutions, it is possible to cost-effectively keep legacy alarm systems while still implementing new telecom site automation solutions.

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