Cisco WS-C3550-48-SMI  Catalyst 3550 10/100 48-Port Switch 48 10/100 ports and 2 GBIC-based Gigabit Ethernet ports 1 rack unit (RU) stackable, multilayer switch upgradeable to full dynamic IP routing Delivers intelligent services Standard Multilayer Software Image (SMI) installed, upgradeable to Enhanced Standard Multilayer Software Image (EMI) Ideal for access and distribution layer connectivity