Behavior when unexpected Role Parameter arrives

[tetter27]

I understand that a ClientSetup is sent that includes the role of Publisher if the client only wants to send objects, the role of Subscriber if it only wants to receive objects, and the role of PubSub if it wants to both send and receive objects. And I believe that basically only the following relationships can be established:

• Client: Publisher vs Server: Subscriber
• Client: Subscriber vs Server: Publisher
• Client: PubSub vs Server: PubSub

My questions are as follows:

1. If a ClientSetup with Subscriber or PubSub role parameters were to arrive at an ingestion-only server, how would the server handle it? Is it required that the server returns Subscriber that the client does not expect and the client understands the server's intention?

2. If a client that has already sent Publisher or Subscriber receives a ServerSetup containing PubSub, is it acceptable to use that connection as is? There may be some security risks in this case.

Thank you!

[tetter27]

As a side note, if the conclusion in #574 will be that Role Parameter is unnecessary or no consideration are required as endpoint behavior, then this issue would be unnecessary.