RCMS Reprot-Link Record

Ever had that sinking feeling when you open a bill that's ten times what you expected? In the world of IoT, this nightmare often comes in the form of cellular data overage charges. A single, misbehaving device in a remote location can silently chew through its data plan, leaving you with a massive, unexpected expense. I've seen it happen, and it’s a painful lesson in the importance of granular monitoring.

This is where your management platform needs to be more than just a dashboard; it needs to be a detective. Within our Robustel Cloud Manager Service (RCMS), the toolbox is deep, but for this job, we need a specific instrument. We're reaching for the RCMS Link Record, a report that I like to think of as a multimeter for your device's data connection. It gives you the raw, detailed truth about your data usage and link quality.

The RCMS Link Record is one of the pre-configured reports we discussed in our overview of RCMS reporting tools. It's a detailed, timestamped log designed to give you a complete picture of your router's WAN and cellular link history.

Unlike a high-level summary, this report gets down to the nuts and bolts. For every reporting interval, it logs data usage (transmit and receive bytes) for the primary WAN and for each individual SIM card. But it doesn't stop there. It also captures a full suite of cellular signal quality metrics, from RSRP and SINR to CSQ and Bit Error Rate. This combination of data usage and signal quality in a single log is what makes the RCMS Link Record an indispensable tool for diagnostics and cost control.

Let me tell you about a scenario I've seen play out. A company deployed dozens of remote sensors for environmental monitoring. Everything seemed to be working perfectly—the devices were online, and data was flowing. Then the finance department called, furious about a bill showing a $500 overage charge from a single SIM card.

What happened? A software update on the connected sensor had a bug, causing it to get stuck in a loop and continuously upload a large log file. From a simple "is it online?" dashboard, everything looked green. But under the surface, this one device was burning through its monthly 5GB data plan in a matter of days.

This is the exact problem the RCMS Link Record is built to solve. By pulling the report for that device, the issue would have been obvious. You would see the (SIM1)TX Bytes value skyrocketing in the logs. The timestamp would allow you to correlate the spike with the exact time the faulty software update was pushed. The problem goes from a costly mystery to a traceable, solvable issue.

The RCMS Link Record is packed with information. Let's break down the key data points into logical groups so you know what you're looking at.

This is your first line of defense against overages. The report tracks data for the general WAN link and for each SIM separately.

• TX/RX Bytes (WAN & SIM1/SIM2): The total transmitted (TX) and received (RX) bytes for the link. This is the raw data you need to monitor consumption against your data plan.
• Delay Time (WAN & SIM1/SIM2): The network latency or ping time. High or erratic delay times can indicate network congestion or a poor connection, even if signal strength looks good.

Data usage is only half the story. Poor signal can lead to retransmissions that inflate data consumption. These five metrics give you a complete health check. You can get a deeper technical explanation of these terms from resources like the 3GPP standards{:target="_blank"}.

• RSRP (Reference Signal Received Power): The most important metric for signal strength. Think of it as "how loud" the cell tower's signal is. A value greater than -90 dBm is excellent.
• RSRQ (Reference Signal Received Quality): Measures the quality of the signal, considering both strength and interference.
• SINR (Signal to Interference plus Noise Ratio): A critical indicator of signal clarity. A higher SINR value (e.g., >15 dB) means a cleaner, more reliable, and faster connection.
• CSQ (Carrier Signal Quality): A more general score from 0-31 that represents overall signal quality. Higher is better.
• Dbm: The raw signal strength in decibels-milliwatts, an alternative to RSRP.

For deep-dive troubleshooting, the Link Record also provides:

• ARFCN: The channel number the radio is using.
• Bit Error Rate: The rate at which errors occur in data transmission.
• ECIO: A measure of signal quality used in 3G networks.

Traceability is great, but prevention is even better. The RCMS Link Record is your diagnostic tool, but RCMS provides two key features to get ahead of the problem.

1. Data Usage Dashboard: For a more intuitive view, RCMS has a graphical dashboard that visualizes traffic usage over time. It’s the perfect complement to the raw data in the Link Record, allowing you to spot trends at a glance.
2. Alerts: This is the most crucial step. You can configure alerts in RCMS to proactively notify you when a device's data usage crosses a certain threshold (e.g., 80% of its monthly plan). An alert turns your raw data into an automated, money-saving action.