The Mellanox itself does not terminate a WAN connection. Please see the following link on page 7 for the supported interconnect cabling options for the SN 2000 series:
http://www.mellanox.com/related-docs/prod_eth_switches/BR_SN2000series.pdf
If this does not answer your question, if you can be more specific about what exactly you are trying to connect it would be helpful.
Kevin