SubscriptionOptions Properties

No local option. If the value is 1, messages MUST NOT be forwarded to a connection with a client identifier equal to the identifier of the publishing connection.

Maximum quality of service option. The maximum level at which the server can send messages to the client.

Retain as published option. If true, messages forwarded using this subscription keep the retain flag they were published with. If 0, messages forwarded using this subscription have the retain flag set to 0. Retained messages sent when the subscription is established have the retain flag set to 1.

Retain handling option. This specifies whether retained messages are sent when the subscription is established. This does not affect the sending of retained messages at any point after the subscribe. If there are no retained messages matching the Topic Filter, all of these values act the same. The values are:

0 = Send retained messages at the time of the subscribe.

1 = Send retained messages at subscribe only if the subscription does not currently exist.

2 = Do not send retained messages at the time of the subscribe.