In: Computer Science
What kind of network management protocols are available? What information can these protocols provide? Explain it with example.
In networking, a protocol is a set of rules for formatting and processing data. Network protocols are like a common language for computers. The computers within a network may use vastly different software and hardware; however, the use of protocols enables them to communicate with each other regardless.
The Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) are used to transmit network data to and from server and client applications. The main difference between the two protocols is that TCP uses a connection-oriented transport, while UDP uses a connectionless type of communication. When the TCP protocol is used, a special connection is opened up between two network devices, and the channel remains open to transmit data until it is closed.
Some common TCP/IP applications are shown with the type of protocol they use.
2. DNS
TCP/IP networks communicate with hosts using their IP addresses. It would be very difficult for someone to have to memorize the different IP addresses for the hosts they want to connect to on the network. A Domain Name Service (DNS) makes it easier to identify a host by a domain name. A domain name uses words rather than numbers to identify Internet hosts.
3. NAT (Network Address Translation)
NAT translates one IP address to another. This can be a source address or a destination address. Two basic implementations of NAT can be used: static and dynamic
With static NAT, a manual translation is performed by an address translation device, translating one IP address to a different one. Typically, static NAT is used to translate destination IP addresses in packets as they come into your network, but you can translate source addresses also.
With static address translation, you need to build the translations manually. If you have 1000 devices, you need to create 1000 static entries in the address translation table, which is a lot of work. Typically, static translation is done for inside resources that outside people want to access. When inside users access outside resources, dynamic translation is typically used. In this situation, the global address assigned to the internal user isn’t that important, since outside devices don’t directly connect to your internal users—they just return traffic to them that the inside user requested.
What information can these protocols provide? Explain it with example.
The amount of protocol information that must be transmitted in a
data communication network to keep track of source and receiver
addresses and of the starting and stopping of messages. Assuming
Poisson message arrivals between each communicating source-receiver
pair, we find a lower bound on the required protocol information
per message. This lower bound is the sum of two terms, one for the
message length information, which depends only on the distribution
of message lengths, and the other for the message start
information, which depends only on the product of the
source-receiver pair arrival rate and the expected delay for
transmitting the message. Two strategies are developed which, in
the limit of large numbers of sources and receivers, almost meet
the lower bound on protocol information.