chap 4

• Switched networks support small to medium-sized businesses by providing secure, reliable, and highly available networks that allow employees to access resources from anywhere in the world
• Data, voice, and video are converged in a switched network to support collaboration using voice systems, IP phones, voice gateways, video support, and video conferencing
• A switched network in a small to medium-sized business includes features such as call control, voice messaging, mobility, and automated attendant to enhance communication and customer service
• Transitioning to a converged network results in substantial savings over managing separate voice, video, and data networks, with integrated IT management for easier moves, additions, and changes
• The Cisco Borderless Network architecture combines innovation and design to support a borderless network that connects anyone, anywhere, anytime, on any device securely, reliably, and seamlessly
• The Cisco Borderless Network provides network services and user and endpoint services managed by an integrated management solution, unifying wired and wireless access with policy, access control, and performance management
• Hierarchical design principles in a borderless switched network ensure maximum availability, flexibility, security, and manageability, with guidelines based on hierarchy, modularity, resiliency, and flexibility
• A borderless switched network is designed in a hierarchical fashion to overlay security, mobility, and unified communication features, with two common hierarchical design frameworks being the three-tier layer and the two-tier layer models
• The three critical layers in a tiered design are the access layer, distribution layer, and core layer, each with specific roles and functions in the campus network
• The access layer provides network access to users, the distribution layer aggregates networks and provides intelligent switching, routing, and network access policy functions, and the core layer serves as the network backbone for fault isolation and high-speed connectivity
• Switched LANs in a hierarchical network offer more flexibility, traffic management, and additional features such as quality of service, additional security, support for wireless networking, and new technologies like IP telephony and mobility services
• Switching in networking and telecommunications involves making decisions based on the ingress port and destination address, with store-and-forward switching providing error checking and automatic buffering, while cut-through switching offers rapid frame forwarding and fragment-free options
• Ethernet switch ports operating in full duplex eliminate collisions, creating separate collision domains for each segment, while half-duplex operation can lead to collisions within the same domain