Previously, the RDMA protocol transport for Qpid supported only Infiniband network interfaces. As a consequence of using Qpid RDMA with an iWarp network interface, the client process was unable to transmit more than 30-40 messages on a single connection due to lost flow control messages. Qpid's usage of RDMA now has changed to support iWarp network interfaces.
Current users of RDMA must upgrade any brokers before upgrading their clients if the upgrade is staged. This upgrade order is necessary because the new brokers can detect both the old and new protocols and switch automatically but the new clients will only use the new protocol.