[OASIS Issue Tracker] (MQTT-502) Handling version 3.x clients

[OASIS Issues Tracker <workgroup_mailer@lists.oasis-open.org>]

     [ https://issues.oasis-open.org/browse/MQTT-502?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ken Borgendale updated MQTT-502:
--------------------------------


What to say about servers and client supporting multiple versions of MQTT was discussed at some length by the TC, and is the subject of MQTT-291 https://issues.oasis-open.org/browse/MQTT-291 . In the end the decision was to say that this spec defines how to handle MQTTv5.0 and we have attempted to make it possible (or even not hard) to support multiple versions of MQTT with the same code. We decided not to define how a client or server defines such multiple version support.


> Handling version 3.x clients
> ----------------------------
>
>                 Key: MQTT-502
>                 URL: https://issues.oasis-open.org/browse/MQTT-502
>             Project: OASIS Message Queuing Telemetry Transport (MQTT) TC
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 5, CSD01
>            Reporter: Ken Borgendale
>             Fix For: 5
>
>
> Could you add a sort of non normative comments about handling version
> 3.x clients for backward compatibility?
> For example:
> What reason code should the broker send with CONNACK for protocol
> error before determining the client version ?
> (Version 3.x clients expect 0x01, while version 5 do 0x81 or 0x82.)
> The broker cannot determine clients version immediately because
> version 5 CONNECT magic word "MQTT" is as same as version 3.1.1.
> How should the broker convert the messages between version 3.x clients
> and version 5 ?
> (Add or delete properties obviously. Anything else to concern ?)
> Regards,
> Tatsuzo Osawa



--
This message was sent by Atlassian JIRA
(v6.2.2#6258)