Cellular traffic size of gateway

Gateways
1

Hello,

I have a Kerlink LoRa IoT Station that captures packets from only two end-nodes. The gateway is connected on a Cellular Network and has installed the Semtech UDP Packet Forwarder. Also, this gateway is located somewhere that covers only these two devices. The cellular connection was configured by following the TTN Documentation.

The physical payload (size in traffic gateway’s) of each device and how often they send their payload are:

  • Device 1

    • DR: SF7BW125, CR: 4/5
    • Uplink Size: 71 bytes
    • Downlink Size: 0 bytes
    • Sends every: 104 seconds

  • Device 2

    • DR: SF7BW125, CR: 4/5
    • Uplink Size: 36 bytes
    • Downlink Size: 12 bytes
    • Sends every: 180 seconds

If I calculate only the traffic from these devices then theoretically the Gateway consumes around 4.8 MBs per month for LoRa packets (uplink and downlink). For some reason I am billed by my cellular provider for 210 MBs (I can see the total consumed megabytes on my bill for this specific sim card) per month.

So my questions are:

  1. Is there a proper way to measure the total traffic of the cellular connection (linux command, logs in kerlink)?
  2. What other cellular traffic does a gateway have except the LoRa packets (uplink and downlink) that would cause this great difference?
  3. Are there any suggestions to limit down the total cellular traffic?

Thank you!

Christos

2

even if you switch off these 2 nodes , you will use data every 30 seconds

3

The gateways send an heartbeat every 30 seconds. Not sure if this can be configured to be less.
Plus, at present you cannot be sure no other LoRa data is collected by the gateway and sent to the network. As far as I understood, future evolutions will include whitelists on gateways with limited bandwidth, to let only selected nodes be forwarded to the network. So you could check whether other nodes use your gateway, for example.
Finally, being a Linux system, maybe there is some other exchange of data outside LoRa, e.g., DNS access etc. You can install a monitor like iftop to look for IP traffic.

The TTN protocol (vs. legacy) should transfer less information, but I do not know much about it.

4

Ok thank you! But what are these extra data for? Are LoRaWAN-unrelated data or is the gateway’s heartbeat? Can I find the size of the hearbeat’s traffic and what exactly is its format?

I am pretty sure there are no other LoRa nodes near the gateway as the gateway is in the middle of nowhere :stuck_out_tongue:. And I also frequently check the gateway’s traffic. The only packets being forwarderd to TTN are from these two devices.