I'm trying to understand the PDU sizes as it traverse the TCP/IP model.
The way I'm reading these RFC's, (RFC 791) is the IP protocol is required to accept a "datagram" of 576 bytes. My interpretation of the term datagram is it's equivalent to a payload. So I'm trying to take that value and figure out how large a PDU will be at the remaining layers.
Listed below are the PDU sizes if I do the math then. Unfortunately, I can't find any confirming information out there that says these values are accurate or not though.
Transport layer
TCP segment size = Header 60 bytes + payload 516 bytes = 576 bytes
UDP datagram = Header 8 bytes + payload 568 bytes = 576 bytes
Internet layer
IP packet size = Header 60 bytes + payload 576 bytes = 636 bytes
Link layer
Ethernet Frame = Headed & FCS 18 bytes + payload 636 = 654 Bytes
The way I'm reading these RFC's, (RFC 791) is the IP protocol is required to accept a "datagram" of 576 bytes. My interpretation of the term datagram is it's equivalent to a payload. So I'm trying to take that value and figure out how large a PDU will be at the remaining layers.
Listed below are the PDU sizes if I do the math then. Unfortunately, I can't find any confirming information out there that says these values are accurate or not though.
Transport layer
TCP segment size = Header 60 bytes + payload 516 bytes = 576 bytes
UDP datagram = Header 8 bytes + payload 568 bytes = 576 bytes
Internet layer
IP packet size = Header 60 bytes + payload 576 bytes = 636 bytes
Link layer
Ethernet Frame = Headed & FCS 18 bytes + payload 636 = 654 Bytes
Last edited: