sfp port specifications: 4-port sfp ; ieee 802.3z compliance supp full duplex operations ; ieee 802.3x compliant flow control support for full-duplex led indicators: link/act led , off - no link , solid green - link blinking green - activity * dem-340mg is a 4-port sfp module designed for the d-link dgs-3212sr managed layer 2 switch or dgs-3312sr managed layer 3 switch * it provides 4-port sfp connection to servers or enterprise core switche