Abstract: A primary communications interface card for receiving a signal is equipped with a bypass or shunting relay, the control of which is managed by a backup or protection interface card. The cable interconnect from far-end equipment to the primary interface card is provided with a make-before-break connector to the primary interface card, and a pig tail cable to the protection card. Upon command, the protection card may command the relay to shunt the signal from the far end equipment around the primary interface card to the protection card. Then, the cable may be disconnected from the primary interface card, with the make-before-break connector providing a signal path from the far-end equipment to the protection card before continuity through the shunting relay is lost. The primary interface card can then be removed and replaced, and the process reversed to redirect traffic to the primary interface card.

Abstract: A method and system for configurable and scalable line interface card protection or redundance useful for a range of low speed digital to high speed digital and optical signal types such as STS-1, STS-3, VT1.5, DS-1/T1, DS-3/T3, ATM, ADSL, HDSL, OC-1, OC-3, OC-12, OC-48, OC-192, OC-768, STM-1, STM-4, STM-16, STM-64, E1, E3, J1, J2, and EtherNet and Token Ring LAN signals. A daisy-chain alternate signal path, signal selectors, and alternate front panel entry points are provided to a front-access telecommunications shelf system. Signal interface cards can be designated as primary cards to handle traffic under normal conditions, or as protection cards, without hardware constrained or slot-specific card requirements. Variations of 1:N protection, and multiple groups of 1:N configurations and partitions can be defined without changes to cabling or backplane design variations through setting of relays and signal selectors on each card.