S3. What is encapsulation, decapsulation, and tunneling? Flashcards
What are encapsulation, decapsulation, and tunneling?
Encapsulation, decapsulation, and tunneling are concepts pertaining to the facilitation of transmission of data across networks
What is encapsulation?
Encapsulation is the process of adding protocol-specific information, in the form of headers and sometimes trailers, to data as it moves down the network stack
Give an example of how data is encapsulated
When data is sent from an application and it is passed down to the transport layer, it is encapsulated with transport protocol headers. Then, at the network layer, IP headers are added, providing information about the destination IP address of the data. Finally, a frame header and trailer are added at the link layer, with eg a checksum
What kind of information do headers contain?
Important information, such as destination addresses, error-checking data, and other protocol-specific information. For example, IP headers contain the destination IP address, IPv4 headers and link-layer frame headers contain a checksum for detecting errors at the receiving end.
What is the purpose of encapsulation?
To ensure that data is properly formatted to be able to reach its destination
What is decapsulation?
Decapsulation is the reverse process in which headers added during encapsulation are removed as data moves up the network layers, until the original data is retrieved and can be delivered to the correct process at the destination host
What is tunneling?
Tunneling involves encapsulating a packet within another packet belonging to a different protocol
What is the purpose of tunneling?
Allowing data to traverse an intermediary network incompatible with the original protocol
What is tunneling commonly used for?
VPNs and IPv6-over-IPv4
How is tunneling used in VPNs?
Private network traffic is encapsulated within public network protocols to securely transmit data across the internet
How is tunneling used in IPv6?
For IPv6 over IPv4 tunnels, in which IPv6 packets are encapsulated in IPv4 packets to allow IPv6 end systems to communicate via infrastructure that is only compatible with IPv4
What is the difference between en/decapsulation and tunneling?
Encapsulation and decapsulation enable structured, layer-specific handling of data, while tunneling allows the traversal of data across diverse network environments
