Draft: Technical Specifications for WIS 2 Nodes for the WIS 2 pilot-phase

Owned by Timo Proescholdt
Last updated: Feb 28, 2023
2 min read

Version 1.2 (28/2/2023)

This page contains information about how WIS 2 Nodes participating in the pilot phase must be registered with the Secretariat and configured. These specifications are intended for the pilot phase only.
Requirements designated must are mandatory ,whereas those designated may are optional. Upper-case spelling designates abstract WIS 2 components (such as WIS 2 Node), whereas lower-case spelling refers to technical components (broker, a MQTT instance).

Registration

To register a WIS2 Node the following information must be sent by email to wis@wmo.int using the subject “WIS2 node registration”:

  • Local broker hostname (e.g. : wis2-pilot.example.com)

  • Port number of MQTT broker (default 1883 and 8883 for MQTT and MQTTS, respectively, or 443 for secured websocket access (WSS))

  • Whether the node supports MQTT over Web Sockets (WS) (recommended since more firewall friendly).

  • Whether TLS is used (MQTTS/WSS are strongly encouraged for security reasons).

  • centre-id used in the topic structure published on the broker. The centre-id represents a unique identifier for the WIS2 node. It can be freely chosen but must be unique. WMO Secretariat will confirm that the proposed centre-id can be used.

  • Country name (using the 3-letter country code from ISO 3166).

  • Administrative contact(s) (Name, email, and role)

The WMO Secretariat will notify the community of newly registered nodes, as needed.

Configuration

  1. A WIS2 node consists of an MQTT broker and a web-accessible resource, typically an HTTP(s) server, exposing the data internationally shared to the WIS2 network. MQTT version 3.1.1 or 5.0 must be used.

  2. Global Brokers must be able to connect to the node through the internet. Global Brokers must be able to use the username/password combination “everyone/everyone” to subscribe to the topic origin/a/wis2/{country_code}/{centre_id}/+/core/# .

  3. The node may limit access on the IP level to the IP addresses used by Global Brokers to subscribe, and by Global Caches to download the data. Public IP addresses of Global Brokers and Global Caches are available from WMO on request.

  4. The WIS2 node may allow the client to subscribe to additional data, for example, by granting access to origin/a/wis2/{country_code}/{centre_id}/#

  5. Notification messages for the topic must correspond to the WIS 2 message format.

  6. The data must be provided separately on an HTTP web server and accessible to the subscriber, as prescribed in the WIS 2 architecture. The use of TLS is strongly encouraged.

  7. The node may offer TLS encryption. If TLS is used, Global Broker must validate that the X.509 SSL certificate provided matches with the hostname and that an accepted Certificate Authority has signed it. Nodes must ensure that certificates are valid and match the hostname provided during registration.