TCP/IP model has been developed much later after OSI model. OSI was developed as theoretical model, while TCP/IP was more practical. TCP/IP is having just four layers in oppose to seven layers of OSI. All the layers are roughly corresponding to the osi model as shown in Figure 1.
Figure 1. The TCP/IP model compared with the OSI model
Application layer is giving access for the applications to the network. Protocols for this layer are:
HTTP (Hypertext Transfer Protocol)
FTP (File Transfer Protocol)
Telnet
NTP (Network Time Protocol)
DHCP (Dynamic Host Configuration Protocol)
PING (Packet Internet Groper)
Transport layer is checking for errors, controlling flow, and sequencing. Protocols for this layer are:
TCP (Transmission Control Protocol)
UDP (User Datagram Protocol)
Internet layer is responsible for routing and address resolution. Protocols are:
IP (Internet Protocol)
IGMP (Internet Group Management Protocol)
ICMP (Internet Control Message Protocol)
ARP (Address Resolution Protocol)
Network Interface layer is handling data formatting and transmission to the network interface .This layer is using Ethernet.
Knowledge of protocols and layers helps determining the problem if it occurs. Error is easier to find if search is narrowed to single layer.
