Cables and wires are used to transfer electricity between devices. A cable contains multiple insulated wires twisted or braided together. A modem connects a computer to an analog telephone line to transmit digital data long distances. Modem speeds have increased over time from 300 bps in the 1960s to 56 kbps in 1998 and higher with technologies like ADSL. A hub and switch connect devices in a network, with a switch being more advanced by only sending messages to requesting devices rather than broadcasting. A server responds to requests to provide network services, and can run on a dedicated computer. A router directs data packet traffic between different networks by reading address information and using its routing table.