A switch operates at the data link layer (Layer 2) of the OSI model and uses MAC addresses to make forwarding decisions. It forwards data only to the specific device associated with the destination MAC address, making it more efficient than a hub.

Star Topology is a network layout where each device is directly connected to a central hub or switch. It's a common choice in local area networks (LANs) as it provides easy management and fault isolation.

The primary purpose of protocols in computer networking is to facilitate communication between devices. Networking protocols define a set of rules and conventions that devices follow to communicate effectively on a network. These rules govern how data is formatted, transmitted, received, and processed across the network.

Subnetting is the process of dividing an IP address space into smaller, more manageable blocks, often called subnets. It is used to efficiently allocate IP addresses and improve network organization and management.

Framing is not typically considered a common error-handling technique in the transport layer. Error detection is used to identify and correct errors in transmitted data. Flow control helps manage the speed of data transmission, and retransmission handles the retransmission of lost or corrupted data.

UDP (User Datagram Protocol) is suitable for streaming videos where occasional data loss is acceptable. UDP is connectionless and does not guarantee data delivery, but it offers lower latency, making it ideal for real-time applications like video streaming.

The "ping" command primarily uses ICMP Echo Request messages to check the reachability of a network device. It sends these messages to the target device, which should respond with an ICMP Echo Reply if it's reachable.

In this scenario, the best technology to ensure that internal servers are not directly accessible from the internet while allowing them to initiate connections to external services is a Proxy Server. A Proxy Server acts as an intermediary, forwarding requests from internal clients to external services while masking the internal server's identity. It provides security and control over outgoing connections. Firewalls and VPNs are primarily used for different purposes, and NAT doesn't provide the necessary level of control.

Port Numbers are numerical labels assigned to specific processes running on a host to differentiate them. These ports are used to direct network traffic to the appropriate applications or services running on a device.

In 10BASE-T, the "10" signifies the network speed, which is 10 Mbps (Megabits per second). This was one of the early Ethernet standards using twisted-pair cables.