InfiniBand will get the fastest throughput, followed by 10 GigE and GigE in which you can get 80 MB/sec throughput. This is enough for real-time playback of SD clips, or about 1/4 real-time for 2K material.
The Visual Effects and Finishing application on the Wiretap server host workstation can also affect performance. Applications have guaranteed access to the local framestores, but remote access by Lustre over Wiretap is at a lower priority. If you notice playback is suffering, consider generating local proxies for the remote material.
To improve real-time playback of RED media, the Wiretap Gateway can spawn multiple slave processes that increase performance without requiring additional licenses.