Frame transmission refers to the process by which data packets, specifically formatted as frames, exit a network system.
Understanding Frame Transmission
Based on the provided definition, transmission is the term used for frames that leave the system, either because they were sent by the system or because they are being forwarded. This simple definition highlights the two primary scenarios where a frame is considered "transmitted":
- Sent by the System: When a device originates a frame (e.g., sending an email, requesting a webpage) and puts it onto the network medium.
- Being Forwarded: When a networking device (like a router or switch) receives a frame from one interface and sends it out another interface to help it reach its destination.
Essentially, frame transmission is the act of a frame exiting a device or network segment to continue its journey across the network.
Why Frames Leave a System
Frames leave a system for fundamental reasons related to network communication:
- Originating Communication: A device generates data to communicate with another device. This data is encapsulated into frames, and the frames must be transmitted out of the local system's network interface.
- Example: Your computer sends an HTTP request frame to a web server.
- Routing or Switching: Intermediate network devices receive frames not destined for themselves but for other devices further along the path. These devices process the frame (checking destination address, etc.) and then forward it by transmitting it out the appropriate exit interface.
- Example: A router receives an IP packet encapsulated in an Ethernet frame on one interface and transmits that frame (or a new frame containing the packet) out another interface towards the destination network.
Key Aspects of Frame Transmission
Understanding frame transmission involves several related concepts:
- Media: Frames are transmitted over physical media like Ethernet cables, Wi-Fi signals, or fiber optic lines. The transmission method depends on the specific network technology being used.
- Networking Devices: Devices like Network Interface Cards (NICs), switches, and routers are responsible for creating, sending, receiving, and forwarding frames.
- Protocols: Network protocols (like Ethernet, Wi-Fi - IEEE 802.11) define the structure of the frame and the rules for transmission on the specific medium.
- Direction: Transmission specifically refers to the outbound movement of a frame from a system or device. The opposite is reception.
Frame transmission is a critical step in delivering data across local networks and the internet, ensuring that information moves from its source to its intended destination.
