The Cisco GSS 4491 Global Site Selector globally load-balances distributed data centers. It is the third addition to the Cisco global site selector product line and with the recently released GSS version 1.2 software provides four new features: Traffic management that routes a client to the closest data center; Global site persistence technology required for e-commerce applications; TACACS+ for secure command and control access; Multiuser roles for complete control of user management capabilities.The Cisco GSS 4491 acts as the cornerstone of multisite disaster recovery plans in deployments of Cisco market-leading content switches. Customers deploying new Cisco content switches such as the Cisco CSS 11500 Content Services Switch and Content Switching Module (CSM) for the Cisco Catalyst 6500 Series switches or customers who have already deployed legacy switches such as the Cisco CSS 11000 and Cisco LocalDirectors can benefit from the new levels of traffic management and centralized command and control provided by the Cisco GSS 4491.The Cisco GSS 4491 delivers the following capabilities: provides a scalable, dedicated hardware platform for Cisco content switches to help ensure that Web-based applications are always available, by detecting site outages or site congestion and rerouting content requests; improves the global data center selection process, by offering user-selectable global load-balancing algorithms; offloads Domain Name System (DNS) servers by taking over the domain resolution process and transmits these requests at thousands of requests per second; scales to support hundreds of data centers or server load balancers (SLBs); complements existing DNS infrastructure by providing centralized domain management; integrates tightly with Cisco SLBs without sacrificing the ability to work in a heterogeneous environment of DNS-capable networking products.