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TCP/IP

What do we need to move information from one place to another on the world wide internet?


1. The address of the computer receiving the information.
2. A system of binary electron, photon, and wireless  bit stream transmission .

TCP stands for Transmission  Control Protocol- Which is used for transmission of packets over the internet. IP stands for Internet Protocol Packets and Address -Which is used to give each and every node on the Internet a unique address.
 
94534-4000 is a USPO zip code. An IP address is like a zip code for a single family dwelling.


 94534-4000 is the unique USPO zip code of 4408 Oakridge Dr. Fairfield, California. 

Only this house in the entire United States has this zip code.

An IP address is a international  system which provides a unique address for each node.  A node can be a computer, scanner, printer, digitizer, or any other device that is hook up to the internet.

An IP address is composed of 32 bits, often shown as a series of four numbers of 2 to the 8th separated by periods. IP addresses can run from 0.0.0.0 to 255.255.255.255. WWW.webopedia.com/DidYouKnow/Internet/2002/IPaddressing.asp will provide an in-depth discussion IP addressing.  176.16.1.2 is a valid IP address.

The current IP addressing allows 4,228,250,625 possible unique addresses on the Internet. Due to the explosive growth another 2 to the 8th place position has been added which will make possible 1,078,203,909,375 unique addresses on the Internet. Additionally another 2 to the 8th position has been allocated for extra terrestrial sites such as the space station and future planetary bases making possible 274,941,996,890,625.

Because we are not trained to think in numeric terms of 4 place positions of 2 to the 8th the Internet Architecture Board developed a registration process which pairs an name with the IP address.

A Domain Name is a unique name that identifies an IP address on the internet.  Not all IP address have a domain name, only those that have been registered.

Solano.edu is the domain name for Solano Community College's web site. 176.16.1.2  is the IP address.

Domain names are portable -  IP address are tied to the network that they are a part of.

For example,  the zip code 94534-4000 refers to a specific house (node) in Fairfield. John Q. Doe (domain name) when he moves from 94534-4000 will go to the post office and put in a change of address card and will continue to use his domain name (John Q. Doe) at the new zip code (IP).

The zip code (IP) is fixed at the address in Fairfield and cannot be changed or used at another address.  The domain name (John Q. Doe) is portable.



 
 

In the XP environment left click start,  left click run, type in CMD, touch enter which will take you to the command prompt.  Type in ipconfig/all and touch enter.

You will see:


 
An Unique IP address of 4 place positions of 2 to the 8th is assigned to each node on the Internet.  Additionally a node may have a domain name which follows IP naming protocol. The domain name is portable but the IP address is fixed.  IP addresses are assigned by the Internet Network Information Center (InterNIC). Domain Names can be registered  at www.networksolutions.org. Now that we know the addressing system how is the binary bit stream packet sent.
 

An IP packet has a minimum length of 576 bytes and a maximum length of 64 Kbytes. The packet has the IP Address of the sender, the receiver, the sequence of the packet of the number of packets being sent and the JOB ID No.  The packet is then placed in an bit stream envelope which contain the TCP instructions

If you had a file that was 2 MBytes long and the hardware that connected to the network only supported 50 KByte packets then it would take 40 packets to send the message.

Header of the packet contains the following information:
To:206.184.13.44
From:185.34.56.213
Job ID: 123456
Packet 1 of 40
This is followed by the Data
And then followed by the Terminus.

Header:
TO: 123.123.123.123
From: 124.124.124.124
Job Id: 123456789
Sequence: 1 of 20
Data up to 64 K Bytes Terminus - end of packet


Transmission  Control Protocol- connection-oriented, reliable.
1. TCP first Pings the site that the message is going to and gets an acknowledgement back from the site that it is ready to receive a packet. At the same time TCP determines the largest packet that can be sent over the connection. The packet is sent.
2. Acknowledgements of receipt of packets by the receiving site is then done.
3. TCP then determines if retransmission of the packet is required.
4. TCP then puts the packets in the proper sequence if required.