2 Frame Relay 4 5 1 3 example essay topic

Introduction This is a formal report that contains two parts. In part one it is to describe 4 types of telephone network services with their features and comparative costs and in part two there are 4 types of services that I need to consider when a business / corporation would use each service in particular situation. Terms of Reference In part one I gave an fully explain for each telephone network service such as data transmission speed and how does it cost. In part two I gave an example and two reasons for when a business / corporation would use a certain service.

Table of Contents: Introduction 1 Terms of Reference 1 Table of Contents 2 1. Part one 3 1.1 Lease line 3 1.2 Value Added Network Facilities (VAN) 3 1.3 Packet Switch 4 1.3. 1 X. 25 4 1.3. 2 Frame Relay 4-5 1.3.

3 ATM 5 1.4 Integrated Service Digital Network (ISDN) 5-6 1.5 Summary 6 2. Part two 7 2.1 Dial-up 2.2 Leased line 2.3 Direct connect 2.4 Packet Switch: Frame Relay 3. References 8 1. Part one 1.1 Lease Lines Leased Lines are dedicated circuits that the Telecom Operator runs directly between two customer sites, providing a permanent connection at a certain speed between the two sites. Two types of Leased Lines are usually offered, Analogue Leased Lines and Digital Leased Lines. Digital Leased Lines offering is more flexible than Analogue Leased Lines in terms of bandwidth, and reaches much higher bandwidth than Analogue Leased Lines.

Digital Leased Lines also offer a better quality of service. Leased digital line speeds range from 9.6 kilobits per second (Kbps) to millions of bits per second (Mbps). "Point-to-point leased line technology is well understood and very reliable. An organization can count on steady, uninterrupted bandwidth and low, predictable delay between two sites when it installs a leased line" (Feit, 1999, p. 119). However, leased lines have a number of disadvantages. They are costly to set up.

Monthly charges are proportional to distance and are substantial. The cost of a fully meshed network is very steep if the sites are far from one another (Feit, 1999, p. 119). 1.2 Value Added Network Facilities (VAN) With the advent of Internet, A value-added network (VAN) is a private network provider (sometimes called a turnkey communications line) that is hired by a company to facilitate electronic data interchange (EDI) or provide other network services (SearchNetworking, n. d. ). Before the arrival of the World Wide Web ( ), some companies communicate and transfer data through a hired value-added network to other companies. After the is released, they found it is cheaper to move their data over the Internet than using VAN because they have to pay monthly fees for it and the cost also depends on per-character data transferring.

This result in some VAN company focus on offering EDI translation, encryption, secure e-mail, management reporting, and other extra services for their customers. 1.3 Packet Switch Packet-switch networks are networks in which data packets can take different routes to reach the same destination (Shinder, 2002, p. 176). Let!'s see the diagram below. A, B, C, D are routers in different location, if a packet of data wants to travel from X to Y it can take several routers till it gets the destination, for example, from X to A then B then reaching Y or from X to A then D then reaching Y. It is fault tolerant because if one router is faulty the data can reach destination through other routers.

A connection is not only for one transmission. Different package can use the same line at the same time. Packet-switching technologies include the following: - X. 25 - Frame Relay - Asynchronous Transfer Mode (ATM) 1.3. 1 X. 25 X. 25 was one of the first packet-switching networks and was designed to work with IBM mainframes, such as the IBM 360, and use analog transmission (Shinder, 2002, p. 176).

It was reliable of data transfer because of including redundant error-checking activity but the performance was slowed by this activity. The ISDN (Public Switched Data Network) running on X. 25 and usually transfers at 64 kbps or below. 1.3. 2 Frame Relay Frame Relay is the high-performance, low-delay solution for cost-effective LAN, WAN Internet and Intranet interconnections. It is a high-speed bandwidth on-demand service interconnecting local area networks throughout New Zealand and across the world (Telecom New Zealand, 2003). A typical Frame Relay implementation used a permanent virtual circuit to provide an always-on connection.

The cost based on the usage so you can avoid the cost of a dedicated leased line. Frame Relay operates only at the two lowest of the OSI model, the physical and data link layers. Frame Relay uses less overhead than X. 25, and thus, it is faster. Frame Relay can run at T-1 and T-3 speeds (from 1.5 Mbps to almost 45 Mbps) (Shinder, 2002, p. 177). Frame Relay has higher performance because it does not include the extensive error checking and correction of X. 25. Frames with errors are discarded, and it is up to the endpoints (communication computers) to detect the missing packet and request retransmission.

Because transmission is digital, there are relatively few errors to contend with, and Frame Relay works well in a WAN environment over T-1 lines (Shinder, 2002, pp. 177-178). It becomes popular because of high performance and cost-effective. 1.3. 3 ATM ATM was designed for high-speed applications such as streaming of audio and video. The advantage of ATM is the fast transfer speed. The transfer rates of ATM are 25 Mbps, 155.520 Mbps, and 622.080 Mbps, and 10 Gbps. But the cost is high.

Moreover, it is expensive to implement because all network hardware must support ATM, and network interface cards, hubs and other ATM-compatible equipment is costly. ATM can both be a direct connection or an on-demand connection. The connection between two endpoints is a virtual circuit, which can be either a PVC or a switched virtual circuit (SVC). ATM can be used for both LANs and WANs using the multiplexing technology.

1.4 Integrated Services Digital Network (ISDN) ISDN is a line capable of transmitting voice, video and data from one location to another. An ISDN line has the flexibility of the standard telephone network with additional high-quality, fast and reliable digital transmission. One ISDN line can manage a business' phone, fax, Internet and data transmission needs. It is called "Integrated Services" because with the connection of readily available ISDN devices, many applications can be supported.

There are two types of ISDN line access - basic and primary Basic Rate Access (BRA) - provides two data or voice lines. You can connect it to a PABX (Private Automatic Branch Exchange), or with appropriate interface equipment, up to eight devices (telephone, computer and fax) can be connected, and any two can operate at the same time Primary Rate Access (PRA) - 30 data or voice circuits, predominantly for voice and data access to medium / large PA BXs. Here is some features of ISDN: - Cost effective and fast transmission of data, voice or video from one location to another - It's economical to manage your business communications with one line - access the internet, send and receive electronic files, email, telephone calls or faxes all from your ISDN connection - It's flexible so you decide how and when the line and connections are used - Fast, quality transmissions you can rely on. 1.5 Summary To sum up the table below shows the 4 types of telephone network service with their features and comparative costs.

Service Name Short Description Type Flexible Speed Cost Lease Lines Permanent connection Analogue Fairly Slower Expensive between two site (cost on per Digital More than 9.6 kbps up Character) Analogue to Mbps Private network Value-Added provider provides N.A. Less Slow Expensive network and other extra network services Data gets destination X. 25 64 kbps below Packet Switch through different Frame Relay Fairly up to 4 Mbps Effective Router ATM up to 10 Gbps A line capable of BRA Fairly ISDN transmitting voice, Fast Effective video and data PRA More Fairly 2. Part two 2.1 Dial-up Dial-up service is a most common Internet connection in the world. This low-cost, easy-to-use dial up service is particularly convenient for business users who travel extensively both domestically and overseas. For example, when you sign up for the alloterra. net (a Global Internet Access Service that provides dial-up connectivity in 40+ countries and more than 3,000+ locations worldwide. ), you receive one dial-up Internet access account and you can use the account to dial up and connect to Internet in any location that the alloterra. net dedicated. 2.2 Leased line Leased line is a private and permanent connection between two sites. Linking banking system would be a good application because it is more secure and it is always connected.

2.3 Direct connect A can be used in an office for two computer back-to-back data transmission. It is a very fast speed and it can share some information and resources, such as printer, file. 2.4 Packet Switch: Frame Relay It is a reliable, high speed and cost effective for a corporation who needs to connect its office Local Area Networks (LANs), host computers and high performance workstations between cities.

Bibliography

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Macmillan network architecture and development series: Wide area high speed networks. Galliard and MCP digital: Macmillan Computer Publishing. SearchNetworking, (n. d. ). Value-added network. Retrieved August 29, 2003, from web Shinder, D.
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Computer networking essentials. Indianapolis: Cisco Press. Telecom New Zealand, (2003).
Frame relay. Retrieved August 29, 2003, from web.