A device's MAC (Media Access Control) address is a unique hardware address assigned to the network card and remains constant, even if the device's IP address changes within a network due to dynamic addressing from DHCP.

Quality of Service (QoS) is crucial in this context. QoS ensures that the network can prioritize gaming traffic to minimize latency and packet loss, providing a better gaming experience for players.

Port Forwarding is a technique used to direct incoming network traffic on a specific port to a designated server or device within a private network. This is commonly achieved through NAT (Network Address Translation) configurations.

The main purpose of the preamble field in a frame is to provide synchronization between sender and receiver. It consists of a specific bit pattern that helps the receiving device identify the start of a frame and synchronize its clock with the sender's clock.

The 100GBase-T Ethernet standard introduced 100 Gigabit per second speeds over twisted-pair copper cables, making it a significant advancement in high-speed networking.

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.

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 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.

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.

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.

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.

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.