The core cross-connect card (CXC) is the central element for ONS 15600 switching. The CXC card establishes connections and performs time division switching (TDS) at STS-1 and STS-Nc levels between ONS 15600 traffic cards.The CXC card works with the TSC card to maintain connections and set up cross-connects within the ONS 15600. You establish cross-connect and provisioning information using TL1 or the CTC software. The TSC card stores the proper internal cross-connect information and relays the setup information to the CXC card.The switch matrix on the CXC card consists of 6, 144 STS-1 ports. When creating bi-directional STS-1 cross-connects, each cross-connect uses two STS-1 ports. This results in 3, 072 bi-directional STS-1 cross-connects. Any STS-1 on any port can be connected to any other port, meaning that the STS cross-connections are non-blocking. Non-blocking connections allow network operators to connect any STS1, STS3, STS12, STS24, STS48 or STS192 payload that is received on an OC-48 or OC-192 interface to any other interface capable of supporting the bandwidth.The CXC card has 128 input ports and 128 output ports capable of STS-48. An STS-1 on any of the input ports can be mapped to an STS-1 output port, thus providing full STS-1 time slot assignments (TSA).