I just curiously wanted to know about the question regarding L4, L3 Data Chunks, IP Fragmentation :
- Data chunking happened at Layer 4(Transport, TCP), and
- Fragmentation at Layer 3(Network, ipv4)
According to Wikipedia, data chunk happens at L4: "Transmission Control Protocol accepts data from a data stream, divides it into chunks, and adds a TCP header creating a TCP segment" Source: https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure
Also, there is fragmentation happening at Layer 3(Network).. Now there are two questions here-
I believe data chunking happening at L4 because of the MTU size limit exceeded, then why there is another process called Fragmentation?
If data chunking is happening or not, there will be a sequence number for each TCP segment.. how can a TCP segment associated with each packet fragment in L3 for successful reassembly at receiver side?
Any help is greatly appreciated..