When using iSCSI port binding, if you have 2 x 10 GbE uplinks to the storage, assuming you are configuring those datastores for a multipathing policy like Round Robin which can use all paths, then all physical links will be used to establish iSCSI sessions to the targets. As far as the path switching frequency, this is dependent upon what the PSP has written in it. On some arrays, the PSP switches ever 1,000 I/Os and others it switches every 1 I/O. When using proprietary MPIO solutions like PowerPath or such, this can vary even further.