There's 2 10Gb base T ports per SP (so 4 per array).  They can be used for NAS or iSCSI or both, but bear in mind you can't use LACP (which you may want for NAS) when using iSCSI.
Hello!   What's the total quantity of 10gb/s BASE-T ports and their usability (Eg., network only, iSCSI only, or capable of any traffic type)?  I believe it's 4, but I've gotten conflicting feedback. Thanks for any help! 
Dell EMC Unity 300 Ports