[ofa-general] librdmacm port selection for rdma_bind_addr()

[Steve Wise]

Sean Hefty wrote:
>> Thanks, For all the sample code, the call rdma_resolve_addr() specify
>> a port number, which is the same as port number when calling
>> rdma_bind_addr()
>> on the other side, 
> 
> Correct - rdma_resolve_addr() does a couple of things:
> 
> 1. It calls rdma_bind_addr() for the local id if it has not already been 
> called.
> 2. It sets the destination address, including port number.
> 3. For IB, it maps the destination IP address to a DGID.
> 
>> I hope port number is not necessary for rdma_resolve_addr() call.
> 
> This is the only call that sets the destination address and port number. 
>  Although the IP address mapping doesn't use the port number, it would 
> still need to be set before calling rdma_resolve_route() to support QoS.
>

Right.  And if you have a service that's using ephemeral ports, then you 
need some way to advertise the port chosen by the transport to your 
clients.   This would be out of band with respect to the rdma connection(s).

Steve.