This paper will attempt to define and contrast the following terms: a. Synchronous and asynchronous b. Analog and digital c. XON and Xoff. Simplex and duplex e. Serial and parallel transmission.
Baseband and broadband g. Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) h. Hypertext transfer protocol (HTTP) and File Transfer Protocol (FTP) i. Transmission Control Protocol (TCP) and Internet Protocol (IP) It will also contain a brief description and analysis of the OSI layers that are used with the TCP/IP protocol stack. Synchronous and Asynchronous In referring to the signal that passes through telephone lines, the transfer methods may be either synchronous or asynchronous.
A synchronous data transfer is sent in a continuous, single stream of characters, grouped into buffered bits. Before the transmission is sent, synchronous characters are sent that set the sending and the receiving ends to the same time. Once affirmation of the syn pulse is returned, the stream is sent to the receiving end. An asynchronous data transfer consists of start and stop bits at the beginning and the end of the pulses that are sent. (Modem, 2004) Analog and digital An analog signal is an exact replica of the sound or picture being transmitted. An analog wave signal is a signal that consists of changing amplitudes of frequencies.
... , malicious nodes, and topologies we can select the best routing protocol to transfer data packets. Hence, by considering the entire test results ... in DSDV and DSR routing protocols. According to Mamoun (2010), the number of out coming packets sent by the neighboring node should ... packet from its original path a route error message is sent to the sender. Hence, sender can identify the malicious node ...
An analog transmission is used over telephone lines to transmit voice frequencies over a carrier frequency through the telephone line. An electric current reproduces the frequency for transmission, then it is converted at the other end back into the sound wave. A digital signal is a square wave signal consisting of a voltage and then a lack of voltage. Digital transmission involves laser lights that flash on and off and are carried through fiber optic lines. This is a very fast transmission rate (approximately 450 flashes per second) and can result in two fiber optic transmission lines to be able to transmit almost 15, 000 conversations at the same time. Digital transmission is faster than analog, and also is more stable, as less noise or other interference can disrupt the signal.
(Thinkquest, 2004) XON and XOFF Control characters like XON and XOFF are used to set limits on the transmission of data. Control characters are used when sending data to a printer, monitor, modem, or other device. XOFF (usually referenced by CTRL+S) is used by the transmitting side at the end of the data pulsed to say that the transmission batch is complete. XON (usually referenced by CTRL+Q) is used to start the transmission, and is found at the beginning of the data pulse.
(Computer Hope, 2004) Simplex and duplex simplex data transmission is only sent one way and without control characters or error signals. An example of a simplex transmission would be the alarm codes that are sent to officials at a burglar alarm company. A half- duplex transmission can send a signal and then receive a signal, but cannot send and receive at the same time. An example would be a CB radio that can send a message, and then listen for the response. A duplex data transmission is capable of sending and receiving data at the same time. A telephone line is an example of a full duplex transmission system.
(Eserver, 2004) Serial and parallel transmission Serial transmission is the consecutive transmission of the signal. The characters are transmitted in a sequence over a single line, rather than simultaneously over two or more lines, as in parallel transmission. Parallel transmission are packets of data sent at the same time, usually over more than one transmission line. This results in faster transmission of data.
... ) guarantees for video transport. The Transmission Control Protocol (TCP) is mainly designed for reliable data traffic. It is not suitable for ... video conferencing, where audio and video signals are created at a remote site, transmitted over the network, and synchronized ... multimedia session. Similar observations were made in wire line networks for audio and video streaming by using multiple ...
Many times, this data is sent sporadically, and start and stop characters are used, along with other control characters to ensure that the receiving end can put the packets back together in the correct order. (Free dictionary, 2004) Baseband and broadband Very simply put, base band transmission is a form of serial transmission in that it transmits only one signal at a time. Broadband transmission is a form of parallel transmission, in that it can transmit multiple signals simultaneously. (Cks lsc, 2004) With regards to a LAN system, a base band system is typically a digital bus network that is capable of transmitting 10 MBps in one direction.
Ethernet is an example of a base band network. A broadband LAN system is a digital system that uses one line to carry many signals, with each signal capable of a greater bandwidth than a base band line could carry. Each signal is carried on a different frequency on the transmission line, and empty spaces called guard bands are used for interference reduction. An example of a broadband system is the cable tv transmission of 100+ channels on a single coaxial cable. (Intersil, 2004) Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) Serial Line Internet Protocol, SLIP, is a TCP/IP protocol used for communication between two machines that have been configured to communicate with each other. For example, my Internet server provider provides a SLIP connection so that the provider’s server can respond to my requests, pass them on to the Internet, and forward my requests back to me via my dial-up connection.
(Searchwebservice, 2004) Point-to-Point Protocol, PPP, is a communication protocol that enables a user to utilize their dial up connection (commonly a modem) to connect to other network protocols like TCP/IP, IPX, etc… Unlike SLIP which is another popular dial up connection protocol PPP offers such new features as password protection and error-correction. (Searchwebservice, 2004) Hypertext Transfer Protocol (HTTP) and File Transfer Protocol (FTP) 2. At what levels of the OSI model does TCP/IP function? 11. At which layers of the OSI model are the primary functions of the TCP/IP and IPX/SPX protocols performed? The TCP/IP, and IPX/SPX protocols function at the Network and Transport Layers of the OSI model.
... Protocol layer operates above the data able bearer services supported by the various network devices. As a general transport service ... well as their patients will insist on these Internet-based environments and the protection and clinical excellence ... H. Improving TCP/IP performance over wireless networks.ACM MOBICOM 95, 1995. WAP Forum. Wireless Application Protocol, Architecture Specification. ...
For this reason, they are often referred to as ‘Network’ and ‘Transport’ protocols. The IP and IPX protocols function at the lower Network Layer by routing and relaying between workstations. TCP and SPX function primarily at the next higher transport layer to provide for the reliability of the communication link. From: web OSI. asp#11 The TCP/IP model does not same as OSI model. There is no universal agreement regarding how to define TCP/IP with a layered model but it is generally agreed that there are fewer layers than the seven layers of the OSI model.
By Ravi Kumar Pal uri, 8/24/2004 TCP/IP model define 4 layers that are as follows: 1) Internet layer: Packet switching network depends upon a connection less internet work layer. This layer is known as internet layer, is the linchpin that holds the whole design together. Its job is to allow hosts to insert packets into any network and have them to deliver independently to the destination. They may appear in a different order than they were sent in each case it is job of higher layers to rearrange them in order to deliver them to proper destination. The internet layer specifies an official packet format and protocol known as internet protocol. The job of internet layer is to transport IP packets to appropriate destination.
Packet routing is very essential task in order to avoid congestion. For these reason it is say that TCP/IP internet layer perform same function as that of OSI network layer. 2) Transport layer: In the TCP/IP model, the layer above the internet layer is known as transport layer. It is developed to permit entities on the source and destination hosts to carry on a conversation. It specifies 2 end-to-end protocols 1) TCP (Transmission Control Protocol) 2) UDP (User Datagram Protocol) 1) TCP It is a reliable connection-oriented protocol that permits a byte stream originating on one machine to be transported without error on any machine in the internet. It divides the incoming byte stream into discrete message and passes each one onto the internet layer.
... layer is the network layer, also called the internet layer in the TCP/IP model, where internet working protocols are defined, the most notable being the Internet Protocol. These two layers ... are related, because messages sent at the network layer ...
At the destination, the receiving TCP process collects the received message into the output stream. TCP deals with flow control to make sure a fast sender cannot swamp a slow receiver with more message than it can handle. 2) UDP It is an unreliable, connection less protocol for applications that do not want TCP’s sequencing on flow control and wish to offer their own. It is also used for client-server type request-reply queries and applications in which prompt delivery is more important than accurate delivery such as transmitting speech or video. Application Layer: In TCP/IP model, session or presentation layer are not present.
Application layer is present on the top of the Transport layer. It includes all the higher-level protocols which are virtual terminal (TELNET), file transfer (FTP) and electronic mail (SMTP).
The virtual terminal protocol permits a user on one machine to log into a distant machine and work there. The file transfer protocol offers a way to move data efficiently from one machine to another.
Electronic mail was used for file transfer purpose but later a specialized protocol was developed for it. The Application Layer defines following protocols File Transfer Protocol (FTP) It was designed to permit reliable transfer of files over different platforms. At the transport layer to ensure reliability, FTP uses TCP. FTP offers simple commands and makes the differences in storage methods across networks transparent to the user. The FTP client is able to interact with any FTP server; therefore the FTP server must also be able to interact with any FTP client. FTP does not offer a user interface, but it does offer an application program interface for file transfer.
... clients and the servers, we can also implement (L2TP) Layer two tunneling protocol and it uses tunneling to deliver the data, also ... employees and the remote network or a VPN. Also secure web protocols to provide a way to authenticate the clients and servers ... needs to maintain a highly available and secure E-mail and web site hosting using the most advance methods in today’s ...
Simple Mail Transfer Protocol By using TCP, SMTP sends email to other computers that support the TCP/IP protocol suite. SMTP provides extension to the local mail services that existed in the early years of LANs. It supervises the email sending from the local mail host to a remote mail host. It is not reliable for accepting mail from local users or distributing received mail to recipients this is the responsibility of the local mail system. SMTP makes use of TCP to establish a connection to the remote mail host, the mail is sent, any waiting mail is requested and then the connection is disconnected. It can also return a forwarding address if the intended recipient no longer receives email at that destination.
To enable mail to be delivered across differing systems, a mail gateway is used. Simple Network Management Protocol For the transport of network management information, SNMP is used as standardized protocol. Managed network devices can be cross examined by a computer running to return details about their status and level of activity. Observing software can also trigger alarms if certain performance criteria drop below acceptable restrictions. At the transport layer SNMP protocol uses UDP.
The use of UDP results in decreasing network traffic overheads. 4) The Host to Network Layer: Below the internet layer is great void. The TCP/IP reference model does not really say such about what happen here, except to point out that the host has connect to the network using some protocol so it can transmit IP packets over it. This protocol is not specified and varies from host to host and network to network.
From: web Retrieved November 20, 2004 from: web Retrieved November 20, 2004 from: web communications / base band broadband. htm Eserver. Retrieved November 20, 2004 from: web 014. htmFreedictionary.
Retrieved November 20, 2004 from: web Retrieved November 20, 2004 from: web Retrieved November 20, 2004 from web Retrieved November 20, 2004 from: web g ci 214211, 00. html Thinkquest. Retrieved November 20, 2004 from web and digital. s html.