2023-09-04 ET-W2AT Meeting

1

Mr Jeremy TANDY

Chair

No

2

Mr Rémy GIRAUD

Member

Yes

3

Mr Pablo Jose LOYBER

Member

No

4

Ms FATIMA SABAI

Member

No

5

Mr Peng  WANG

Member

Yes

6

Mr Tom KRALIDIS

Member

No

7

Mr Kenji TSUNODA

Member

No

8

Dr Baudouin RAOULT

Member

No

9

Mr Thorsten BÜSSELBERG

Member

No

10

Ms Dana OSTRENGA

Member

No

0

Opening

Rémy

Rémy introduces the participants and Andre Fatton from VerneMQ.

ET-W2AT discusses pub/sub, hiearchary and notification message format. Few parameters

Using standards, to describe further implementation of standards as baselines.

MQTT parameters. Recording of today’s meeting will be shared with ET-W2AT members.

1

Presentation on advanced MQTT features

Andre Fatton, VerneMQ

• MQTT Basics

• MQTT QoS (Quality of Service)

Discussions:

• (Kai) any nodes to subscribe to at least 2 brokers for redundancy. Question: connection failures, share data over protocol, retain message?

  • (Andre) Retained message / offline messages, persistent sessions. For offline messages, persistent session is needed. Offline for one hour, estimate the volume of the messages that were missed. For the broker administrator, all subscribers go offline, network failed, queue size limit. If the time window is too big, no broker can do this part. MQTT is different from database.

• (Rémy) shares the flow of messages in WIS2 to alert a WIS users of data availability.

• Persistent sessions

• (Hassan) WIS2 users and messages with different priorities, QoS for user/message priorities settings?

  • (Andre) Publishers will set their QoS = 1 or 2 on their own.

  • (Rémy) no necessary to prioritize at message level. Challenge is more on subscriber side.

  • (Kai) It is more on dowloading side, for large volume, it is important to download by priority.

  • (Andre) Queue Priority no needed for MQTT specification.

• (Rémy) Next step is to write MQTT parameters specification in one or two pages

• (Hassan) MQTT Security?

  • (Andre) MQTT is secure by utilizing measure in the form of in the form of MQTT level username, password, and an access control list (ACL)