Network Infrastructure , TCP/IP Port , TCP/IP , Protocol

       Module  III   ( Network  Infrastructure)

Protocol

Protocol means set of rules or language of network. Protocol means communication language of computers or software programming to send and receive bits. There are different types of protocols like TCP/IP,    IPX/SPX,    AppleTalk  etc.

TCP/IP

It can be use in very large network, it can provide very high security and we cannot access Internet without TCP/IP.    TCP/IP is a protocol suite or protocol stack, it is combination of more than 2,600 protocols. The main protocols in TCP/IP suite are :-

1. TCP (Transmission Control Protocol)        It is connection-oriented and reliable protocol, it can guarantee the delivery of packets, it use windowing process and use acknowledgement. Windowing process means some packets will be send to destination and if acknowledgement will be receive then more packets can be send. TCP can wait for acknowledgement until TTL works. Time To Live is particular time in seconds for which packet will remain on network. Maximum size of packet or datagram is 64KB.

Windowing process use WinSock (Windows Socket) protocol.

2. UDP (User Datagram Protocol)      It is connectionless and non-reliable protocol, it does not guarantee the delivery of packets, it does not use windowing process and it is faster than TCP. It can be use in small network.

3. ICMP (Internet Control Message Protocol)    It works with Ping and Tracert commands. ICMP is use to check network connection and for network troubleshooting by collecting the network information. ICMP can provide messages like  Reply, Request time out, Destination host unreachable etc.

4. IGMP (Internet Group Management Protocol)     It can make group of computers which belongs to same network and it can make the connectivity faster in a particular network. IGMP is mostly use in multicasting.

5. ARP (Address Resolution Protocol)     It can resolve IP address into MAC address. Data can be deliver to the physical address and not to the logical address.

6. IP (Internet Protocol)   This protocol is use for logical connection, it is a carrier protocol, it is faster and it can also stop broadcasting.

TCP/IP Port

These are logical ports. OS use some number to identify any protocol or service which are known as Port numbers.  Port numbers are assign by IANA (Internet Assigned Numbers Authority). Maximum port numbers are 1 to 65535 and well-known port numbers are  1 to 1024. For example :-

HTTP=80,  HTTPS(SSL)=443,  RPC=145,  IMAP=143,   POP=110,  NNTP=119,   SMTP=25,   Telnet=23,   SSH=22,   FTP21,   LDAP=389,   Global Catalog=3268,   DNS=53,   DHCP server=67,   DHCP client=68,   RIP=520,  IGRP=9,  OSPF=89,   EIGRP=88,  Kerberos=88,  ICMP=1   etc.