Supported Protocols

The IoT Emulator supports multiple IoT communication protocols.

LWM2M (Lightweight M2M)

LWM2M is a device management protocol designed for IoT devices, built on top of CoAP.

Features

Device registration and lifecycle management
Resource observation and notification
Firmware update support
Bootstrap support

Default Ports

CoAP over UDP: 5683 (unsecured), 5684 (DTLS secured)
CoAP over TCP: 5883 (unsecured), 5884 (TLS secured)

The transport (UDP/TCP) and concrete port are chosen in the Protocol Options tab.

Protocol Options

These are the defaults used by the emulator (from lwm2m_gui.properties); the Protocol Options tab exposes many more advanced fields (OSCORE, firmware/software update timing, DTLS CID, content format, thread counts, etc.).

Option Default Description

Option	Default	Description
Version	1.0	LWM2M Enabler version — `1.0` or `1.1`
Transport	UDP	`UDP` (CoAP) or `TCP`; pairs with the port selector above
Registration Lifetime	6000	Registration validity in seconds (`lifetime`)
Registration Timeout	600	Seconds to wait for a registration response (`lwm2m.regtimeout`)
ACK Timeout	10000	CoAP acknowledgment timeout in ms (`ack_timeout`)
Bootstrap	false	Register against a bootstrap server before the management session (`bootstrap`)
Notification Type	CON	`CON` (confirmable) or `NON` (non-confirmable) observe notifications (`lwm2m.notification.type`)

Version

1.0

LWM2M Enabler version — 1.0 or 1.1

Transport

UDP

UDP (CoAP) or TCP; pairs with the port selector above

Registration Lifetime

6000

Registration validity in seconds (lifetime)

Registration Timeout

600

Seconds to wait for a registration response (lwm2m.regtimeout)

ACK Timeout

10000

CoAP acknowledgment timeout in ms (ack_timeout)

Bootstrap

false

Notification Type

CON

CON (confirmable) or NON (non-confirmable) observe notifications (lwm2m.notification.type)

MQTT

MQTT is a lightweight publish-subscribe messaging protocol.

Features

Publish/Subscribe messaging
QoS levels (0, 1, 2)
Retained messages
Last Will and Testament

Default Ports

MQTT: 1883 (unsecured)
MQTTS: 8883 / 8884 (TLS secured)

Protocol Options

The Protocol Options tab for MQTT exposes the fields below (from mqtt_gui.properties).

Option Default Description

Option	Default	Description
Username	(empty)	MQTT broker username (optional)
Password	(empty)	MQTT broker password (optional)
QoS Level	1	Quality of Service for publish/subscribe — `0`, `1` or `2`
Port	1883	Broker port — `1883` (plain), `8883` / `8884` (TLS)

Username

(empty)

MQTT broker username (optional)

Password

(empty)

MQTT broker password (optional)

QoS Level

Quality of Service for publish/subscribe — 0, 1 or 2

Port

1883

Broker port — 1883 (plain), 8883 / 8884 (TLS)

Keep-alive (30 s), connection timeout (30 s) and max-inflight are set by the underlying Paho v3 client and are not exposed in the UI. The proprietary FSH_HUB and DUSUN protocols are built on this MQTT client and override the default QoS.

CoAP (Constrained Application Protocol)

CoAP is a specialized web transfer protocol for constrained devices.

Features

RESTful interface (GET, POST, PUT, DELETE)
Observe pattern for subscriptions
Block-wise transfers
DTLS security

Default Ports

CoAP: 5683 (unsecured)
CoAPS: 5684 (DTLS secured)

Protocol Options

Option	Default	Description
ACK Timeout	2000	Acknowledgment timeout in ms
Max Retransmit	4	Maximum retransmission attempts
Block Size	512	Block size for transfers

Option

Default

Description

ACK Timeout

2000

Acknowledgment timeout in ms

Max Retransmit

Maximum retransmission attempts

Block Size

512

Block size for transfers

USP (User Services Platform)

USP (TR-369) is the next-generation protocol for device management, replacing TR-069.

Features

Controller-Agent architecture
Four Message Transfer Protocols (MTPs): STOMP, CoAP, WebSocket, MQTT
Protobuf message encoding
Bulk data collection
Configurable session handling, onboarding and TLS host-name verification

Default Ports

Each MTP has its own plain/secured port pair (selected in the Protocol Options tab):

MTP	Plain	Secured
STOMP	61617	61618
CoAP	5783	5784 (DTLS)
WebSocket	8025	4430 (TLS)
MQTT	18881	18882 (TLS)

Protocol Options

Option Default Description

Option	Default	Description
MTP	STOMP	Message Transfer Protocol — `STOMP`, `CoAP`, `WebSocket` or `MQTT`; selecting one enables the matching port dropdown
Endpoint ID	auto	Agent endpoint identifier (`server_endpoint` / `usp.mqtt.client_id`)
Protocol Version	1.0	USP protocol version — `1.0` or `1.2` (`usp.version`)
MQTT QoS	1	QoS for the MQTT MTP — `0`, `1` or `2` (`usp.mtp.mqtt.qos`)
MTP Ping Interval	0	Seconds between MTP keep-alive pings, `0` = off (`usp.mtp.ping_interval`)
MQTT Connect Retry Time	5	Minimum delay (sec) between MQTT reconnect attempts. Maps to `usp.mtp.mqtt.connect_retry_time` and corresponds to TR-181 `Device.MQTT.Client.{i}.ConnectRetryTime`.
MQTT Connect Retry Max Interval	30720	Maximum delay (sec) for the exponential reconnect backoff. Maps to `usp.mtp.mqtt.connect_retry_max_interval` (TR-181 `ConnectRetryMaxInterval`).
MQTT Connect Retry Interval Multiplier	2000	Backoff multiplier in units of 0.001 (informational; the underlying Paho v5 client uses its own exponential schedule between min and max). Maps to `usp.mtp.mqtt.connect_retry_interval_multiplier` (TR-181 `ConnectRetryIntervalMultiplier`).

MTP

STOMP

Message Transfer Protocol — STOMP, CoAP, WebSocket or MQTT; selecting one enables the matching port dropdown

Endpoint ID

auto

Agent endpoint identifier (server_endpoint / usp.mqtt.client_id)

Protocol Version

1.0

USP protocol version — 1.0 or 1.2 (usp.version)

MQTT QoS

QoS for the MQTT MTP — 0, 1 or 2 (usp.mtp.mqtt.qos)

MTP Ping Interval

Seconds between MTP keep-alive pings, 0 = off (usp.mtp.ping_interval)

MQTT Connect Retry Time

Minimum delay (sec) between MQTT reconnect attempts. Maps to usp.mtp.mqtt.connect_retry_time and corresponds to TR-181 Device.MQTT.Client.{i}.ConnectRetryTime.

MQTT Connect Retry Max Interval

30720

Maximum delay (sec) for the exponential reconnect backoff. Maps to usp.mtp.mqtt.connect_retry_max_interval (TR-181 ConnectRetryMaxInterval).

MQTT Connect Retry Interval Multiplier

2000

Backoff multiplier in units of 0.001 (informational; the underlying Paho v5 client uses its own exponential schedule between min and max). Maps to usp.mtp.mqtt.connect_retry_interval_multiplier (TR-181 ConnectRetryIntervalMultiplier).

When the USP agent is bound to MQTT, an unexpected disconnect triggers automatic reconnect with the delay range above. After a successful reconnect the agent re-subscribes to its reply-to topic so that pending controller requests can resume.

TLS Authentication

When the USP agent communicates with the MQTT broker over TLS, the emulator supports both mutual (client + server) authentication and server-only authentication. The mode is controlled by the FT_TLS_AUTH environment variable (or -Dft.tls.auth JVM property): 1 (default) enables mutual auth, 0 switches to server-only auth.

See TLS Authentication Mode in the Installation Guide for details and examples.

FSH_HUB

Proprietary protocol for FSH Hub smart-home gateways. It is built on top of the MQTT client (JSON-RPC over MQTT) and overrides the default QoS to 2.

Transport

MQTT broker, ports 1883 (plain) / 8883 (TLS) — same as MQTT
Default QoS 2 (exactly-once delivery)

Topics

The emulated hub subscribes to and publishes on the friendlytech/oneiot/api/v1/… topic namespace:

Topic Direction Purpose

Topic	Direction	Purpose
`friendlytech/oneiot/api/v1/rpc/request`	subscribe	Incoming RPC requests (`get` / `set` / `delete` on parameters)
`friendlytech/oneiot/api/v1/events/response`	subscribe	Event acknowledgements from the server
`friendlytech/oneiot/api/v1/rpc/response`	publish	RPC responses back to the server
`friendlytech/oneiot/api/v1/events/*`	publish	Telemetry events and parameter updates

friendlytech/oneiot/api/v1/rpc/request

Incoming RPC requests (get / set / delete on parameters)

friendlytech/oneiot/api/v1/events/response

Event acknowledgements from the server

friendlytech/oneiot/api/v1/rpc/response

publish

RPC responses back to the server

friendlytech/oneiot/api/v1/events/*

publish

Telemetry events and parameter updates

Protocol Options

In addition to the MQTT fields, the FSH Hub Protocol Options tab (from fsh_hub_gui.properties) exposes a sensor-scanning simulator:

Option Default Description

Option	Default	Description
`async_scan_sensors`	true	Scan/attach sensors asynchronously instead of blocking
`bulk_sensor_addition`	true	Add all sensors in a single bulk operation
`sensor_addition_delay`	1000	Delay in ms between sensor additions (when not bulk)
`sensor_categories`	PowerMeter,DoorBell	Comma-separated list of sensor categories to generate
`sensors_count`	1	Number of sensors to create per category

async_scan_sensors

true

Scan/attach sensors asynchronously instead of blocking

bulk_sensor_addition

true

Add all sensors in a single bulk operation

sensor_addition_delay

1000

Delay in ms between sensor additions (when not bulk)

sensor_categories

PowerMeter,DoorBell

Comma-separated list of sensor categories to generate

sensors_count

Number of sensors to create per category

DUSUN

Protocol support for Dusun gateway devices. Like FSH_HUB it rides on the MQTT client (JSON messages over MQTT), but overrides the default QoS to 0 (at-most-once).

Transport

MQTT broker, ports 1883 (plain) / 8883 (TLS)
Default QoS 0

Topics

The gateway is addressed by its MAC address:

Topic Direction Purpose

Topic	Direction	Purpose
`t/{mac}`	subscribe	Commands addressed to the gateway
`t`	publish	Reports/responses from the gateway

t/{mac}

Commands addressed to the gateway

t

publish

Reports/responses from the gateway

Message Format

Messages are JSON with a reportAttribute envelope, for example:

{
  "type": "reportAttribute",
  "from": "GATEWAY",
  "to": "CLOUD",
  "mac": "30:ae:7b:26:2d:46",
  "deviceCode": "...",
  "time": 1717579200,
  "data": { }
}

DUSUN currently has no dedicated _gui.properties file — it reuses the MQTT connection settings and a fixed gateway MAC. There is no separate *Protocol Options page for it.