The ONS 15454 DS3N-12 card provides twelve Telcordia-compliant, TR499 DS-3 ports per card. Each port operates at 44.736 Mbps over a single 75 ohm 785A or equivalent coaxial span.You can install the DS3N-12 card in any multispeed or high-speed card slot. Each DS3N-12 card port features DSX-level outputs supporting distances up to 450 feet depending on facility conditions. With the proper backplane EIA, the card supports BNC or SMB connectors.The DS3N-12 can operate as the protect card in a 1: N (N<5) DS-3 protection group. It has additional circuitry not present on the basic DS3-12 card that allows it to protect up to five working DS3-12 cards. The basic DS3-12 card can only function as the protect card for one other DS3-12 card. Other than the protection capabilities, the DS3-12 and DS3N-12 cards are identical.