The network layer (Internet Layer in TCP/IP model) is the second layer of the TCP/IP model. IP (Internet Protocol), ARP (Address Resolution Protocol), RARP (Reverse Address Resolution Protocol), ICMP (Internet Control Message Protocol) and IGMP (Internet Group Management Protocol) are the protocols at this layer. http://www.omnisecu.com/tcpip/internet-layer.htm
tcp is the transport control protocol and ip is the internet protocol. tcp is concerned with guaranteed delivery of packets from source to destination, while ip is the protocol used to actually deliver packets. tcp is located at layer 4 of the osi model, or the transport layer. ip is located at layer 3 of the osi model, or the network layer. check out the video tutorials in the link below.
Transport layer and Network layer.
There are exactly four layers Application layer Trasport layer Internet layer similar to n/ w layer in OSI model N/w interface like data link layer. TCP/IP model doesnt have physical layer , presentation layer and session layers.
The TCP/IP model was adopted and condensed into 4 Layers.1. Link layer ( Layer 1and 2 of the OSI model)2. Internet Layer (Layer 3 of the OSI model)3. Transport ( Layer 4, 5 and 6 of the OSI model)4. Application ( Layer 7 of the OSI model)http://en.wikipedia.org/wiki/TCP/IP_model#Link_Layer
TCP/IP because the osi model has seven layer but in tcp/ip only four layers and most important is that the tcp/ip model is reduce the function of osi model.
transport layer processes occur between the applicaitoin layer and internet layer of the TCP/IP and between the session layer and network layer of the OSI model.
internet
The "Internet" layer in the TCP/IP model more or less corresponds to the "Network" layer (layer 3) of the OSI model. Both have the task of connecting different networks, independently on the type of layer-2 network; and of providing addresses to every machine on the Internet.
smtp, http, anything on that specific OSI layer.
The Transport layer
The Network Interface layer