CS601 - Data Communication (GDB)

To build networks, those who designed them started with the idea of separating networking functions in to discrete layers. Each layer performs a specific function and is transparent to the layer above it and the layer below it.

The TCP/IP Model of networking is a different way of looking at networking. Because the model was developed to describe TCP/IP, it is the closest model of the Internet, which uses TCP/IP.

All application data, whether it is an e-mail, a file, an instant message, a video or voice call, is chopped into data segments and encapsulated in Transport Layer PDU's (TCP or UDP segments). The Transport Layer PDU's are then encapsulated in Internet Layer's Internet Protocol packets. The Internet Protocol packets are then chopped into frames at the Network Access layer and transmitted across the physial media (copper wires, fiber optic cables or the air) to the next station in the network.

The OSI Model uses seven layers, and differs quite a bit from the TCP/IP model. The TCP/IP model does a better job of representing how TCP/IP works in a network, but the OSI Model is still the networking model most technical people refer to during troubleshooting or network architecture discussions.

We're going to teach you the TCP/IP model from the top down beginning with the Application Layer.

Arfa Karim Randhawa, (9-year-old earns accolade as Microsoft Professional )

Born	2 February 1995 Chak No. 4JB Ram Dewali, Faisalabad, Pakistan
Died	14 January 2012 (aged 16) Lahore, Pakistan
Resting place	Chak No. 4JB Ram Dewali, Faisalabad
Residence	Lahore
Nationality	Pakistani
Education	A-level (first year)
Alma mater	Lahore Grammar School
Occupation	Student
Known for	World's youngest Microsoft Certified Professional, 2004-200
Awards	Fatimah Jinnah Gold Medal Salaam Pakistan Youth Award President's Pride of Performance

Early life

9-year-old earns accolade as Microsoft Professional

Cardiac Arrest

Offer By Bill Gates

Signs Of Improvement

Death

Arfa Karim Technology Park

Arfa Karim of Multan has officially become the youngest MCP in Pakistan, and one of the youngest in the world. Karim, now 10, met with Microsoft Chairman Bill Gates last week--an experience she later described as second only to visiting Disneyland.

To attain the credential--at any age--a person has to display technical proficiency in areas such as .Net, Visual Studio 6.0 and Windows Server 2003.

Karim got excited about technology, when her father bought her a computer--primarily to use for e-mail, according to S. "Soma" Somasegar, a corporate vice president in Microsoft's tools division.

"What she wants to do as she grows up--she would love to study at Harvard, work in a company like Microsoft and go back to Pakistan to do technology innovations in the field of satellite engineering," Somasegar wrote in his blog last week.

Somasegar describes her as the youngest MCP in the world, but according to a Channel News Asia report, the youngest ever to attain that qualification is India's Mridul Seth, who is said to have gained it at age 8 in November 2004.

According to Microsoft, Karim is part of a select group, as one of only a few certified professionals in the world to qualify below the age of 10.

Karim has been honored for her achievement by the Mir Khalil-ur-Rehman Foundation in Karachi, where she was presented with an award for excellence. She was the first recipient of the award, which will honor students "who have displayed exemplary achievements and skills in their respective fields." For her efforts, Karim was also given a computer.

Arfa Karim Randhawa, (Arfa Karim Technology Park)

On 15 January 2012, in Arfa's funeral prayers Chief Minister of the Punjab Shahbaz Sharif has
changed the name of Software Technology Park to Arfa Karim Technology Park.

Arfa Karim Randhawa, (Death)

On 14 January 2012, 16-year-old Arfa Karim died at 9:50 PM (Pakistan Standard Time) at Combined Military Hospital (CMH) Lahore. Her Namaz-e-Janaza was offered in Cavalry Ground Lahore at 10 AM on 15 January 2012, and later at Faisalabad the same day. The funeral was attended by Chief Minister of Punjab Shahbaz Sharif. She was buried at her ancestral village Chak No. 4JB Ram Dewali, Faisalabad.

Arfa Karim Randhawa, (Signs Of Improvement)

On 13 January 2012, Arfa Karim started to improve and some parts of her brain showed signs of improvement. Her father, Amjad Karim Randhawa, said Microsoft had raised the possibility of flying Arfa to the US for care.

The condition of world's youngest MCP Arfa Karim is improving and some parts of her brain have shown signs of improvement.

Arfa fell desperately ill last month and doctors say she has suffered brain damage, leaving her in a coma at the Combined Military Hospital (CMH) in Lahore.

Her father, Amjad Karim Randhawa, said Microsoft had raised the possibility of flying Arfa to the US for care.

She was only nine years, nine months and 11 days old when she became the world's youngest Microsoft Certified Professional -- a qualification usually gained by IT professional and software developers -- after demonstrating her proficiency with the company's software.