I work at an ISP supporting business customers' networks. I primarily work with customers with multiple locations that they have interconnected via my company's MPLS VPN product. Scale really varies from 2 sites to some customers with over 600 sites. I am very proficient in TCP/IP, Cisco IOS, VOIP (primarily on a Cisco platform), a wide range of transmission mediums (T1s, DSL, metro Ethernet), and I make an excellent cup of coffee.