This page lists Cloud IoT Core requirements and related information.
Regions and versions
Only these cloud regions are available:
Cloud IoT Core requires version 173.0.0 or higher of the Cloud SDK.
Transport Layer Security (TLS)
Cloud IoT Core requires TLS version 1.2 or higher. For more guidance on TLS, see the section "Minimum standards for TLS clients" in Disabling SSLv3 and RC4 on the Google Security Blog.
MQTT version 3.1.1 is required.
The following features are not supported:
- MQTT QoS 2
- Arbitrary MQTT topics and subscriptions. For topic requirements, see the section on connecting devices using MQTT
- Last Will and Testament (LWT)
- Retained messages
- Persistent sessions
Secure communication (HTTPS) is required.
Cloud IoT Core supports HTTP 1.1 only (not 2.0).
Permitted characters and size requirements
Registries and device identifiers, and their associated fields, are limited to certain characters. These fields are also limited in size (either length or byte size).
The following table lists the permitted characters and sizes for each resource:
|Device metadata keys||
|Device metadata values||
"Subfolders" refers to the
eventNotificationConfigs.subfolderMatches field in
the device registry, which is used when matching
MQTT or HTTP subfolders to a Cloud Pub/Sub topic. For
more information, see
Creating a device registry with multiple Pub/Sub topics.