Application Data, TCP Header, IP header, and Ethernet Header in an Ethernet (Data Link Layer) Frame

Data Link Header
22 bytes
(preamble 8,
dst mac 6,
src mac 6,
type 2)

Network (IP) Header
20 bytes

Transport (TCP) Header
20 bytes

(Application Layer Message)
Transport (TCP) Data
(MSS=1460 or 536)

(Transport Segment)
Network (IP) Data

(Network Datagram)
Data Link Data (MTU=1500 or 576)

Data Link Trailer
(CRC = 4 bytes)