Limitations

The following table lists the technical specifications of IoTDA. If the specifications cannot meet your service requirements, submit a service ticket to describe your requirements.

**Table 1** Resource restrictions
Category	Object	Description	Limit
Instance management	Standard edition instance	Number of units purchased for a standard instance (see Specifications of Standard Edition)	100
Resource space management	Resource space	Number of resource spaces supported by an instance	10
Device access	MQTT	MQTT protocol standard	Supported: MQTT v3.1, v3.1.1, and v5.0; not supported: QoS 2, and will, and retained messages
		Security levels supported by MQTT	TLS 1.1, TLS 1.2, and TLS 1.3
		Heartbeat interval of MQTT connections (see Establishing a Connection)	Range: 30s to 1200s; recommended: 120s (If the heartbeat interval is not within the range, the server will reject the connection request.)
		Maximum timeout interval = Heartbeat interval x 1.5 (If no device message is received within the maximum timeout interval, the server automatically disconnects from the device.)
		Number of connections established between a device and IoTDA	1
		Length of a custom MQTT topic	128 bytes
		Size of a message reported by an MQTT device	1 MB (A message larger than this size is rejected.)
		Number of subscriptions for an MQTT connection	50
		Bandwidth of an MQTT connection	1 Mbit/s
		Number of upstream messages per second for an MQTT connection	50
		Number of connection requests created per second for an instance	Specifications of Standard Edition
		Number of upstream requests for an instance per second on the device side (assuming that the average payload of a message is 512 bytes)	Specifications of Standard Edition
	CoAP/LwM2M	CoAP version	RFC 7252 standard 3
		LwM2M version	V1.0.2
		Transport layer protocol	User Datagram Protocol (UDP)
		Security level supported by CoAP	DTLS v1.2
		Size of a CoAP message packet	1 KB
		Number of messages per minute for a device	300
	HTTP	HTTP versions	HTTP 1.0 and HTTP 1.1
		TLS versions	TLS 1.1 and TLS 1.2
		Size of a message body	1 MB
Device management	Product	Number of products in a resource space	1,000
		Size of the service capability JSON file in a product	500 KB
		Number of services in a product	500
		Number of properties, events, or commands in a service capability	500
	Custom topic	Number of custom topics for a product	50
	Number of devices in a standard instance	Number of devices registered for a standard edition (SU1, SU2, SU3, and SU4)	2,000,000 (If you want to increase the limit, submit a service ticket.)
	Number of devices in a standard instance	Number of devices registered for an SUF	1,000
	Device	Number of child devices added to a gateway	50,000
	Device	Depth of the gateway structure	2 levels
	Device tag	Number of tags added to a device	10
	Group	Depth of a group	5 levels
		Number of groups in a resource space	1,000
		Number of devices in a group	20,000
		Number of groups that a device can be added to	10
	Batch task	Number of devices registered at a time	100,000
	Codec	Number of codecs allowed in a product	1
		Size of the codec package uploaded offline	4 MB
		Length of the codec script	1 MB
		Timeout interval for a codec invoking request	5s
	Device linkage rule	Number of rules added for an instance	Basic/Standard edition: 20
		Number of rules added for an instance	Enterprise edition: 200
		Number of actions supported by a rule	10
		Number of rule actions executed by devices per second for an instance	Basic/Standard edition: 10
			Enterprise edition: 100
		Number of waiting tasks for an instance	Basic/Standard edition: 100
		Number of waiting tasks for an instance	Enterprise edition: 1,000
	Batch task	Number of batch tasks concurrently processed in a resource space	10
		Size of a batch task file	2 MB
		Number of lines in a batch task file	100,000
		Number of batch task files supported by an instance	10
	OTA upgrade	Size of an upgrade package	Package uploaded to IoTDA: 20 MB; package uploaded to OBS: no limit
		Number of upgrade packages uploaded to a resource space	200
		Size of a file uploaded to a resource space	File uploaded to IoTDA: 500 MB; file uploaded to OBS: no limit
Message communications	Synchronous command	Response time of a device to a synchronous command	20 seconds
	Device message	Aging time of a message delivered to a device	24 hours
		Size of a message delivered to a device	256 KB
		Number of cached messages to be delivered to a device	20
	Device property	Number of child devices of which properties can be reported by a gateway at a time	100
	Asynchronous command	Aging time of an asynchronous command delivered to a device	48 hours
		Size of an asynchronous command delivered to a device	256 KB
		Number of cached asynchronous commands delivered to a device	20
Message forwarding	Forwarding rule and action	Number of rules configured for an instance	100
		Number of actions supported by a rule	10
		Length of the select parameter in a forwarding rule	0.5 KB
		Length of the where parameter in a forwarding rule	0.5 KB
	Cache policy for message forwarding	Message cache size	1 GB
	Cache policy for message forwarding	Message cache duration	24 hours
	AMQP	AMQP version	AMQP 1.0
		TLS version	TLS 1.2
		Number of queues configured for an instance	100
		Number of queues listened on for a connection	10
		Number of connections allowed in an instance	32
	Flow control and stack policies	Number of data forwarding stack policies	1
	Flow control and stack policies	Number of data forwarding flow control policies	4
Certificate management	Certificate configuration	Number of device CA certificates supported by an instance.	100
Certificate management	Certificate configuration	Number of application CA certificates supported by an instance.	10