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The underlying assumption in the connection management algorithm is that both sides are exchanging messages. If there is a change in the call flow where one side simply sends events with the other side not responding using IMMEDIATE messages, the initiating side will run out of credits and will be stuck since none of the credits are being returned.
It might be better to return the credit on an IMMEDIATE message once the tx is completed. When receiving immediate message do not increment ibc_outstanding_creditsThat's why we have the NOOP message. The intent is to monitor the outstanding credits on the connection and once they pass the peer_credits_hiw mark, then the NOOP message eagerly returns the credits to the other side of the connection to allow it to continue sending.
Queue Depth Negotiation
Queue depth is negotiated as follows:
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