Q & A about PORT
1: What is a header and why is it significant to TCP/IP?
** A header is a series of bits that is prepended to application data by TCP, UDP, and IP. These bits provide essential pieces of information that facilitate the communications between these protocol suites on the source and destination machines during a communications session.
2: What function is served by a port address?
** A port address uniquely identifies the application in a communications session. Two port addresses exist in each communications session: one to identify the source application and the other to identify the destination application.
3: What's the difference between a source port address and a destination port address?
** A source port address identifies the address of the application that initiated the conversation. A destination port address is the address of the recipient of that conversation.
4: What's the difference between a well-known, registered, and dynamic port address?
** A well-known port address can only be assigned to system-level processes. Assignment of well-known port addresses is carefully regulated by IANA, as there are only 1,024 possible addresses. These range from 0 to 1023.
A registered port address is also regulated by IANA, but these numbers can be assigned to applications run by users. Registered port numbers range from 1024 to 49151.
Dynamic port addresses are selected on the fly from a pool of available or unused port addresses. The pool of possible addresses starts at 49151 and runs up to 65535.
5: What are the four most important network-oriented functions provided by IP?
** IP performs four critical functions:
- Creating an envelope for carrying data through a network or internetwork.
- Providing a numeric addressing system that lets you uniquely identify virtually every machine in the Internet around the world.
- Enabling each envelope or data packet to be specifically addressed to its intended destination. This address is the packet's destination IP address.
- Enabling each envelope or packet of data to also tell the recipient machine who sent it. This return address is the source IP address.
6: What are the two most important network-oriented functions provided by UDP?
** UDP's two most critical functions include
- Accepting data from an application and wrapping a UDP header around it. The combined structure of UDP header and application data is known as a datagram. Unlike TCP, UDP doesn't have to segment its data. The type of applications that use UDP are such that only small quantities of data typically are passed at a time to UDP. The datagram is handed to IP for further processing.
- Verifying whether the data in the datagram was damaged in transit. If the data is found undamaged, it is handed to its intended destination application. If the data appears to have been damaged, the entire datagram is discarded.
7: What are the six most important critical network-oriented functions provided by TCP?
** TCP's top six functions include
- Chopping up application data into bite-sized chunks known as segments
- Managing the communications session
- Guaranteeing that data gets delivered to the correct destination machine and application
- Finding and fixing any damage that occurs to data when it traverses the network
- Ensuring that any data lost in transit is replaced
- Reassembling data received into a perfect copy of the application data that was sent
** A header is a series of bits that is prepended to application data by TCP, UDP, and IP. These bits provide essential pieces of information that facilitate the communications between these protocol suites on the source and destination machines during a communications session.
2: What function is served by a port address?
** A port address uniquely identifies the application in a communications session. Two port addresses exist in each communications session: one to identify the source application and the other to identify the destination application.
3: What's the difference between a source port address and a destination port address?
** A source port address identifies the address of the application that initiated the conversation. A destination port address is the address of the recipient of that conversation.
4: What's the difference between a well-known, registered, and dynamic port address?
** A well-known port address can only be assigned to system-level processes. Assignment of well-known port addresses is carefully regulated by IANA, as there are only 1,024 possible addresses. These range from 0 to 1023.
A registered port address is also regulated by IANA, but these numbers can be assigned to applications run by users. Registered port numbers range from 1024 to 49151.
Dynamic port addresses are selected on the fly from a pool of available or unused port addresses. The pool of possible addresses starts at 49151 and runs up to 65535.
5: What are the four most important network-oriented functions provided by IP?
** IP performs four critical functions:
- Creating an envelope for carrying data through a network or internetwork.
- Providing a numeric addressing system that lets you uniquely identify virtually every machine in the Internet around the world.
- Enabling each envelope or data packet to be specifically addressed to its intended destination. This address is the packet's destination IP address.
- Enabling each envelope or packet of data to also tell the recipient machine who sent it. This return address is the source IP address.
6: What are the two most important network-oriented functions provided by UDP?
** UDP's two most critical functions include
- Accepting data from an application and wrapping a UDP header around it. The combined structure of UDP header and application data is known as a datagram. Unlike TCP, UDP doesn't have to segment its data. The type of applications that use UDP are such that only small quantities of data typically are passed at a time to UDP. The datagram is handed to IP for further processing.
- Verifying whether the data in the datagram was damaged in transit. If the data is found undamaged, it is handed to its intended destination application. If the data appears to have been damaged, the entire datagram is discarded.
7: What are the six most important critical network-oriented functions provided by TCP?
** TCP's top six functions include
- Chopping up application data into bite-sized chunks known as segments
- Managing the communications session
- Guaranteeing that data gets delivered to the correct destination machine and application
- Finding and fixing any damage that occurs to data when it traverses the network
- Ensuring that any data lost in transit is replaced
- Reassembling data received into a perfect copy of the application data that was sent
posted by Arivu at
5:51 pm
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