Aug 28, 1980

RFC 768 - User Datagram Protocol Aug 28, 1980 IPv6 packet - Wikipedia An IPv6 packet is the smallest message entity exchanged using Internet Protocol version 6 (IPv6).. Packets consist of control information for addressing and routing and a payload of user data. The control information in IPv6 packets is subdivided into a mandatory fixed header and optional extension headers. The payload of an IPv6 packet is typically a datagram or segment of the higher-level Layer 2 Ethernet frame sizes — Netrounds documentation 2 The maximum frame size depends on the interface MTU (Maximum Transmission Unit); the default value is 1500 bytes. The minimum frame size for IPv4 is 64 bytes, where the Ethernet header takes up 18 bytes, the IPv4 header 20 bytes, and the UDP header 8 bytes.

However, the size of the receiver window of each TCP endpoint is indicated in each TCP header sent from that endpoint, not just during the 3-way handshake. My question is what happen if the receiver's window size(not sure whether window size matters for UDP communication) or MTU size is smaller than the received packet size?

Tcp header format explanation - TCP Flags, TCP Ack, Header Apr 22, 2020 Headers: UDP & TCP

Protocol Header Cheetsheets — Pingfu

Difference Between TCP and UDP (with Comparison Chart