# Gateway receives a lot of incompatible LoRaWan data?

**URL:** <https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252>\
**Category:** Dragino Gateways\
**Created:** [August 1, 2022, 10:40am UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252 "2022-08-01T10:40:47Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![GerbenvdBerg](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/gerbenvdberg/32/35697_2.png) [@GerbenvdBerg](https://www.thethingsnetwork.org/forum/u/GerbenvdBerg)\
**Post date:** [August 1, 2022, 10:40am UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252/1 "2022-08-01T10:40:47Z")

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One of my gateways is using a lot of (cellular) data, and I found out it is receiving lots of messages that don’t seem to follow the LoraWan protocol.

The gateway is a Dragino DLOS8.  
I’m wondering if the receiver could be defect, or that it maybe is just seeing messages from a private LoRa network?

The ‘wrong’ messages show up like this in the TTN terminal:

```auto
"data": {
      "@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
      "namespace": "pkg/encoding/lorawan",
      "name": "field_length_with_multiple_choices",
      "message_format": "`{lorawan_field}` length `{value}` should be equal to `{expected_1}` or `{expected_2}`",
      "attributes": {
        "expected_1": 17,
        "expected_2": 33,
        "lorawan_field": "JoinAcceptPHYPayload",
        "value": 19
      },
      "correlation_id": "442d755cc86d4e369238d3a33a069ca4",
      "code": 3
    }

```

```auto
"data": {
      "@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
      "namespace": "pkg/encoding/lorawan",
      "name": "decode",
      "message_format": "could not decode `{lorawan_field}`",
      "attributes": {
        "lorawan_field": "RejoinRequestPayload"
      },
      "correlation_id": "13bc2b42ea7b44b5891c04f13f859231",
      "cause": {
        "namespace": "pkg/encoding/lorawan",
        "name": "unknown_field",
        "message_format": "unknown `{lorawan_field}`",
        "attributes": {
          "lorawan_field": "RejoinType",
          "value": "92"
        },
        "correlation_id": "5a2819c420a541cb8b5b3dc6b2905cca",
        "code": 3
      },
      "code": 3
    },

```

```auto
"data": {
      "@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
      "namespace": "pkg/errors",
      "name": "validation",
      "message_format": "invalid `{field}`: {reason}",
      "attributes": {
        "field": "m_hdr",
        "name": "MessageValidationError",
        "reason": "embedded message failed validation"
      },
      "correlation_id": "285ff2f83bbc47119bbb10f7a4bd94a6",
      "cause": {
        "namespace": "pkg/errors",
        "name": "validation",
        "message_format": "invalid `{field}`: {reason}",
        "attributes": {
          "field": "major",
          "name": "MHDRValidationError",
          "reason": "value must be one of the defined enum values"
        },
        "correlation_id": "04023f10ffc34f0d836f492b5ce73b63",
        "code": 3
      },
      "code": 3
    },

```

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<div class="post-metadata">

**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\
**Post date:** [August 1, 2022, 11:17am UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252/2 "2022-08-01T11:17:55Z")

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Check to see if you have “do not send packets with CRC errors” and “do not send packets with no CRC” set to on - that will stop badly formed packets and packets that don’t meet the normal format from being sent over cellular.

It will still send proper LoRaWAN packets as gateways can’t tell who they are for - but it will at least filter out these ones.

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<div class="post-metadata">

**Author:** ![GerbenvdBerg](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/gerbenvdberg/32/35697_2.png) [@GerbenvdBerg](https://www.thethingsnetwork.org/forum/u/GerbenvdBerg)\
**Post date:** [August 1, 2022, 11:59am UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252/3 "2022-08-01T11:59:30Z")

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Couldn’t find the settings you mention in the UI of dragino, but from the logread I can tell that it is only forwarding packets with a valid CRC:

```auto
daemon.info lora_pkt_fwd[7797]: REPORT~ # RF packets received by concentrator: 6
daemon.info lora_pkt_fwd[7797]: REPORT~ # CRC_OK: 50.00%, CRC_FAIL: 50.00%, NO_CRC: 0.00%
daemon.info lora_pkt_fwd[7797]: REPORT~ # RF packets forwarded: 3 (57 bytes)
daemon.info lora_pkt_fwd[7797]: REPORT~ # PUSH_DATA datagrams sent: 3 (765 bytes)

```

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<div class="post-metadata">

**Author:** ![wolfp](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/wolfp/32/45304_2.png) [@wolfp](https://www.thethingsnetwork.org/forum/u/wolfp)\
**Post date:** [August 2, 2022, 5:45am UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252/4 "2022-08-02T05:45:21Z")

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If the data-package is forwarded by the gateway it is a LoRaWAN-package with a valid CRC. But TTN is not the only one using LoRaWAN, there are a few other providers e.g. Helium, Loriot… using LoRaWAN technologies of Semtech.  
The Gateways do not inspect the contents of a valid LoRaWAN -package, they just forward it to e.g. TTS (The Things Stack). There the decision is made whether to discard the data-package or to use it.  
I receive a LoRaWAN -beacon that is transmitting 19 byted every 12 seconds and several Helium-devices. They all are causing traffic not intended for TTN. But the data-packages are all sent to TTS.

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<div class="post-metadata">

**Author:** ![system](https://www.thethingsnetwork.org/forum/uploads/default/original/3X/6/2/6250ea44fd2b0d6259489e1a92748df681e1f970.png) [@system](https://www.thethingsnetwork.org/forum/u/system)\
**Post date:** [August 4, 2022, 3:43pm UTC](https://www.thethingsnetwork.org/forum/t/gateway-receives-a-lot-of-incompatible-lorawan-data/58252/5 "2022-08-04T15:43:46Z")

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