Editing Connectionless communication (section)

==Architecture and implementations==
Distinction between connectionless and connection-oriented transmission may take place at several layers of the OSI Reference Model:
* [[Transport layer]]: [[Transmission Control Protocol|TCP]] is a connection-oriented [[transport protocol]]. [[User Datagram Protocol|UDP]] is connectionless.
* [[Network layer]].
* [[Data link layer]]: The [[IEEE 802.2]] protocol at the [[Logical Link Control]] sublayer of the data link layer may provide both connectionless and connection-oriented services. In fact, some [[network protocol]]s (such as [[Systems Network Architecture|SNA]]'s [[Path Control]] in its early stages) require a connection-oriented data link layer. Others (like [[Internet Protocol|IP]]) do not. (After the appearance of [[IBM Advanced Peer-to-Peer Networking|APPN]], SNA could operate on a connectionless data link service as well.)

Notable connectionless protocols are: [[Internet Protocol]] (IP), [[User Datagram Protocol]] (UDP), [[Internet Control Message Protocol]] (ICMP), [[Internetwork Packet Exchange]] (IPX), [[Transparent Inter-process Communication]],  [[NetBIOS]], and [[Fast and Secure Protocol]] (FASP).