Port Numbers In Computer Networks Port Numbers In Computer Networks


Port Numbers In Computer NetworksPort Numbers In Computer Networks



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A port is an endpoint of communication in an operating system. While the term is also used for female connectors on hardware devices, in software it is a logical construct that identifies a specific process or a type of network service.

When referring to a network or to the Internet, a software or network port is a location where information is sent. For example, port 80 is the HTTP network port. A listing of commonly known and used ports can also be found on the below listing.

  • 18 – MSP (Message Send Protocol)
  • 20 - FTP (File Transfer Protocol) for data transfer
  • 21 – FTP (File Transfer Protocol) for data control
  • 23 – Telnet
  • 22 – SSH - Remote Login Protocol
  • 25 - SMTP (Simple Mail Transfer Protocol) for is used for sending mails.
  • 53 – DNS (Domain Name System)
  • 67 – DHCP (Dynamic Host Configuration Protocol) for sending data to the server – Bootps
  • 68 – DHCP (Dynamic Host Configuration Protocol) for data to the client - Bootpc
  • 80 – HTTP (Hypertext Transfer Protocol)
  • 109 – POP2
  • 110 - POP3 (Post Office Protocol) used for receiving mails but it uses log-in process.
  • 119 – NNTP (Network News Transfer Protocol)
  • 137 – NetBIOS Name Service
  • 139 – NetBIOS Datagram Service
  • 143 – IMAP4 (Interim Mail Access Protocol) used for receiving mails.
  • 150 – NetBIOS Session Service
  • 161 – SNMP
  • 179 – BGP (Border Gateway Protocol)
  • 389 – LDAP (Lightweight Directory Access Protocol)
  • 443 – HTTPS (HTTP-secure)
  • 546 – DHCP Client
  • 547 – DHCP Server
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What is Bitcoin and How it Works

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Bitcoin is a form of digital currency, created and held electronically. It allows you to move money without being traced because all transactions are anonymous. Bitcoins are just lines of computer code that hold monetary value. Those lines of code are created by electricity and computers. Bitcoin was the first crypto coin currency ever invented. Bitcoin’s “creator” is known as Satoshi Nakamoto. They have never been identified.

Bitcoin can be used to buy things electronically. The Bitcoin idea was to produce a currency independent of any central authority, transferable electronically, more or less instantly, with very low transaction fees. .

How a Bitcoin Transaction Works .

If Alice sends some bitcoins to Bob, that transaction will have three pieces of information:.

An input. This is a record of which bitcoin address was used to send the bitcoins to Alice in the first place (she received them from her fr...

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Combinations and Permutations

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Permutation and combination related questions are common in PSC and Bank exams.

Before going to Combinations and Permutations, first lean about factorial. .

If \'n\' is a positive integer then, factorial of n is denoted as n! . .


5! = ( 1 x 2 x 3 x 4 x 5 ) = 120.

4! = (1 x 2 x 3 x 4 ) = 24.


Permutations are for lists of items, whose order matters and combinations are for group of items where order doesn’t matter. in other words, .

When the order of items doesn\'t matter, it is called as Combination.
When the order of items does matter it is called as Permutation.


The number of permutations of n objects taken r at a time is determined by using this formula:.

P(n,r)=n!/(n−r)! .

Permutation : Listing your 3 favourite football team in order, from list of...

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മലയാള കൃതികൾ - കേന്ദ്ര സാഹിത്യ അക്കാദമി അവാർഡ്

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.

കൃതി രചയിതാവ് .
ഭാഷാസാഹിത്യചരിത്രം ആർ. നാരായണപണിക്കർ .
പാണിനീയപ്രദ്യോതം ഐ.സി. ചാക്കോ .
ചെമ്മീൻ തകഴി ശിവശങ്കരപ്പിള്ള .
കഴിഞ്ഞകാലം കെ.പി. കേശവമേനോൻ .
സുന്ദരികളും സുന്ദരന്മാരും പി.സി. കുട്ടികൃഷ്ണൻ .
വിശ്വദർശനം ജി. ശങ്കരക്കുറുപ്പ് .
അയൽ‌ക്കാർ പി. കേശവദേവ് .
മുത്തശ്ശി എൻ. ബാലാമണിയമ്മ .
കല ജീവിതംതന്നെ കുട്ടികൃഷ്ണമാരാർ .
താമരത്തോണി...

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