Stateless Packet Filters
Payload is the actual data which is being transmitted (as opposed to the headers and routing information).
TCP
Packets are never repeated in a network because information in their headers will always change (sequence id, checksums, etc.). The data may be repeated, but that is only a part of the packet.
routing protocol: helps to find the best path to transfer the packets from one network to diffrent network example: rip: routing information protocol igrp, ospf...... routed protocol: helps to carry the packets to the destination. example: smtp : transfer the mails ftp : transfer the files.
File transfer protocol
osi
The IP protocol creates all IP packets.
PACKETS
A "protocol" is a set of rules used in networking, for a particular purpose. IP (the Internet Protocol) is the protocol used to transmit packets over various networks.TCP (the Transmission Control Protocol) is the protocol which (among other things) ensures a high degree of reliability over inherently unreliable networks. That is, individual IP packets may be lost, but TCP ensures that they are retransmitted. TCP/IP is a protocol suite - in other words, a group of related protocols. It is named after two important protocols, explained, above, but it actually includes various other protocols as well.
internet
Connection-oriented protocol
IP (Internet Protocol)