Just in case you are using Hybrid configuration here - 10Gb network is only required for All-Flash.
We do not actually give official recommendations on what throughput will be sufficient as this is dependent on the utilisation (and potentially contention if other traffic is sharing the switch(es)) and other factors that result in more network traffic (e.g. RAID5 and/or Stretched clusters). The general advice is that if you think the Network will be the main bottleneck (e.g. All-NVMe using RAID6 Storage Policy) to use the best you can afford and preferably the deeper the buffers the better.
The listed requirements for maximum latency etc. and other considerations can be found here: