Network layer
 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (October 2009) |
| OSI model by layer |
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In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers.[2]
The network layer provides the means of transferring variable-length network packets from a source to a destination host via one or more networks. Within the service layering semantics of the OSI network architecture, the network layer responds to service requests from the transport layer and issues service requests to the [[data link layer
Relation to TCP/IP model
The TCP/IP model describes the protocols used by the Internet.[3] The TCP/IP model has a layer called the Internet layer, located above the link layer. In many textbooks and other secondary references, the TCP/IP Internet layer is equated with the OSI network layer. However, this comparison is misleading, as the allowed characteristics of protocols (e.g., whether they are connection-oriented or connection-less) placed into these layers are different in the two models.[citation needed] The TCP/IP Internet layer is in fact only a subset of functionality of the network layer. It describes only one type of network architecture, the Internet.[citation needed]
Protocols
The following are examples of protocols operating at the network layer.
References
- Tanenbaum, Andrew S. (2003). Computer networks. Upper Saddle River, New Jersey: Prentice Hall. ISBN 0-13-066102-3.
External links
- OSI Reference Model—The ISO Model of Architecture for Open Systems Interconnection, Hubert Zimmermann, IEEE Transactions on Communications, vol. 28, no. 4, April 1980, pp. 425 – 432. (PDF-Datei; 776 kB)