Today's Web service providers must understand Quality of Service, filtering techniques and implement QOS and access list filters on their networks. A proper QOS and filtering design helps to avoid network bottlenecks caused by worm and virus infections, sudden spikes in traffic, broadband users, file sharing, and other network conditions. Service providers can use QOS and filtering techniques to align network usage with business policies and requirements, all while still serving customers and supporting their own back office needs. This presentation covers the key concepts of quality of service and access-list filtering using open source tools. The presentation includes an explanation of filtering using Linux's iptables tool and standard queuing methods as defined in the Differentiated Services RFC as well as applications of these methods through generic case studies.