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DATAGRAM / TELEMETRY

Inspect UDP device traffic, one datagram at a time.

Capture telemetry datagrams, verify device identification and investigate replies without trying to infer message boundaries from a stream.

Start UDP testing →Read the setup guide

SingleIoT product guide · Updated October 14, 2026

UNDERSTAND THE EXCHANGE

What can you test with UDP?

UDP testing is useful when devices send compact telemetry as independent datagrams. Each datagram becomes a frame in SingleIoT’s UDP gateway. To investigate missing telemetry, start with the assigned endpoint and device identity, then compare the captured datagram with the bytes your device sent.

01

Gateway destination

Verify the hostname and UDP port assigned to your device, including network and firewall reachability.

02

Device identification

Use the configured token-prefix, source-address or supported protocol-identifier mode.

03

Datagram payload

Inspect each captured datagram independently and compare payload bytes with your expected message.

SET UP YOUR FIRST TEST

How to test a UDP device in SingleIoT

  1. 1

    Create a UDP device

    Check UDP availability on your plan and copy the assigned gateway destination.

  2. 2

    Configure identity

    Use the authentication or identifier mode shown in the device workspace. Token-prefix mode includes the device token before the payload.

  3. 3

    Send one known datagram

    Send a small test message as one datagram. Verify the destination and compare the received frame with the bytes sent by the client.

  4. 4

    Test replies from the same sender

    Check any configured acknowledgement and reply behavior using the same sending socket. Observe network address translation and reply timing when diagnosing missing replies.

UDP connection example

Start with a known message, then compare it with the captured frame.

UDP · illustrative setup
One datagram in token-prefix mode:

<device token>\n{ "temperature": 26.5, "battery": 98 }

Captured payload:
{ "temperature": 26.5, "battery": 98 }

The displayed \n is a newline separator between the token and payload. Send the token and payload together in one datagram. Other device identification modes use the configuration assigned to the device.

Common UDP testing problems

Change one setting at a time and use captured traffic to verify the result.

No datagram appears

Check the assigned UDP port, destination address, network path and device identifier. Verify that you are viewing the intended device workspace.

Datagram is not attributed to a device

Confirm the token prefix or pinned source address. Identifier-mode devices need a supported protocol definition and the expected identifier in their payload.

Reply is missing

Check whether a reply rule matches the incoming payload. Replies return to the sender’s source address, so socket lifetime and NAT mapping can affect whether the client receives them.

Received bytes differ from your source

Verify encoding, token separators and datagram length. Inspect the hex view before assuming the payload is text.

UDP testing questions

How are UDP messages separated?

The UDP gateway treats each received datagram as one frame. Unlike TCP, it does not use stream delimiter or length-prefix framing to separate consecutive datagrams.

Can UDP devices receive commands?

The gateway can send replies and queued commands to the sender’s source address after a datagram. Delivery depends on the device’s behavior and the network path, including NAT mapping lifetime.

See what your UDP device actually sends.

Create a device workspace and inspect your first frame.

Create your workspace →