You will be unable to access the device by telnet until you configure an IP address. You will need a console cable connected to the switch and the serial port on your computer. Set hyperterminal or other serial port terminal app (putty or teraterm) to 9600,8,n,1. Boot up the Cisco switch and then you should be able to configure the device. Find a configuration guide from <a href=”http://www.cisco.com/en/US/products/hw/switches/ps5528/products_installation_and_configuration_guides_list.html”>Cisco here</a>.