TASK 1 EVALUATE THE PERFORMANCE OF COMMUNICATION SYSTEMS Task 1.1 Performance of the Available Communication Technologies Analog Telephone Lines/ Analog Modems. These use the existing telephone infrastructure to link sites together. The telephone cabling supports analogue frequencies in the range 300Hz to 3400KHz, and is primarily designed for speech. The available bandwidth of the speech circuits provided by telecommunication companies (e.g. SLT, Suntel) imposes limits on the available speed in bits per second that can be transmitted. The modems implement a dial-up connection. A connection is made between the two modems by dialing the number assigned to the other modem, using the existing dial up telephone network. Generally modems fail to achieve the maximum speeds they depict. Errors caused by noise on the telecommunication lines often cause modems to fall back to a much lower speed, in order to reduce the number of errors. Thus a high speed modem rated at 33600bps often achieves a throughput of 9600bps due to the existing phone lines being too error prone to support the higher rate. Another problem that occurs is with modems that utilize compression techniques. Often, compression is measured on the transmission of uncompressed files like text files. When these same compression modems are asked to deal with the transfer of compressed files, they do not perform well, and effectively either transfer at a much reduced rate or no compression at all. In addition, modems utilizing the different compression schemes often fail to communicate properly with compression enabled. This is due to variances in manufacturers implementations of compression algorithms. Advantages of implementing the analog lines at Aitken Spence Widely available Low cost Most interoperate reliably Disadvantages of implementing the analog lines at Aitken Spence Low speed Error Prone ISDN – Integrated Service Digital Network ISDN provides end-to-end digital connectivity between any two (or more) communications devices. This can be thought of as an alternative to the existing public switched telephone network (PSTN). Information enters, passes through, and exits the network in a completely digital fashion. Many aspects of telecommunications are improved with digital technology. For example, digital technology lends itself to very large-scale integration. Technology and its associated benefits of efficiency and cost reduction. In addition, computers operate digitally. Digital transport provides for human-to-human, computer-to-computer, and human-to-computer interactions. The ISDN is capable of transporting voice, data, graphics, text, and even video information over the same equipment. The customer has access to a wide spectrum of communications services by way of a single access link. This is in contrast to existing methods of service access, which segregate services into specialized lines. Associated with integrated access and ISDN is the concept of a standard interface. The objective of a standard interface is to allow any ISDN terminal to be plugged into any ISDN interface, resulting in terminal portability, flexibility, and ease in operation. Ways in which ISDN can be connected Fig 1.1 The above figure shows An ISDN terminal adapter with phone support (ISDN modem) allows a telephone, fax machine and PC to communicate via the ISDN service. Fig 1.2 The figure 1.2 depicts that LANs typically connect to ISDN via a router, which enables multiple users to share the available channels. For Internet access, the router supplies temporary IP addresses to each of the nodes. Routers may also provide analog phone support. Services that can be provided at Aitken Spence with ISDN Fast file transfer - The user don't need to courier or post text, photographs, drawings, video clips, etc. With ISDN this can be done between computers in seconds. ISDN - Data interchange is made within seconds instead of hours waiting at a normal dial-up connection terminal. Fast internet access- Enables the user to search and download information from the Internet at twice the speed of the fastest analogue modem and save time and money on searching and downloading. Network connectivity - With ISDN, the user can combine two local area networks as one can allow data flow within these networks. Call line identification - Displays the number of the person who calls before the user answer a call and throughout the call. Video conferencing - Enables the user to hold face to face meetings with people around the world; discuss and amend documents, images in real time without having to move from the desk. Moreover talk to customers, businessmen, and other dignitaries face to face without having to travel thousands of miles. Remote network access - Allows the user to work from home and make his/her work efficient and effective. With ISDN one can access information held on the network and use the same applications. E-mail - Transference of memos, letters, invoices, statements. G4 faxes - Faxing becomes 7 times faster with ISDN. If an A4 size page takes 10 seconds to fax under normal circumstances, with ISDN it takes only 1.5 seconds. At present the ISDN service is available in Sri Lanka through Sri Lanka Telecom (SLT). Refer appendix 1 for the current service areas and the charges for ISDN. The details were taken from the SLT City Office – Kandy. Advantages of Implementing ISDN at Aitken Spence Low fixed cost Scalable Fast call set up times Based on digital technology and provides a very low ber (bit error rate) Perfect clarity, reliability and speed. Disadvantages of Implementing ISDN at Aitken Spence Not available in all cities ( e.g. Kandy, Kalutara) Not suited to mobile users (users dialling in via remote access) Digital Subscriber Line (xDSL) xDSL is a high speed solution that allows megabit bandwidth from telecommunications to customers over existing copper cable, namely, the installed telephone pair to the customers premises (called the local loop). xDSL offers significant increases in connection speed and data transfers for access to information. In many cases, the cost of relaying fiber optic cable to subscriber premises is prohibitive. As access to the Internet and associated applications like multimedia, tele-conferencing and on demand video become persistent, the speed of the local loop is a limiting factor. xDSL is a number of different technologies that provide megabit speeds over the local loop, without the use of amplifiers or repeaters. This technology works over non-loaded local loops (loaded coils added by telephone companies on copper cable pairs to improve voice quality). xDSL coexists with existing voice over the same cable pair, the subscriber is still able to use their telephone, at the same time. This technology is referred to seamless. To implement xDSL, a terminating device is required at each end of the cable, which accepts the digital data and converts it to analogue signals for transmission over the copper cable. In this respect, it is very similar to modem technology. xDSL provides for both symmetric and asymmetric configurations. Asymmetric Symmetric Bandwidth is higher in one direction Bandwidth same in both directions Suitable for Web Browsing Suitable for video-conferencing Variations of xDSL There are currently six variations of xDSL. xDSL Technology Meaning Rate 2 x 64Kbps circuit switched 1 x 16Kbps packet switched (similar to ISDN-BRI) DSL Digital Subscriber Line HDSL High-bit-rate DSL S-HDSL/SDSL Single-pair or Symmetric 768Kbps over a single pair High-bit-rate DSL ADSL Asymmetric DSL up to 6Mbps in one direction RADSL Rate Adaptive DSL An extension of ADSL which supports a variety of data rates depending upon the quality of the local loop VDSL Very High-bit-rate asymmetric DSL Up to 52Mbps in one direction and 2Mbps in the other direction. 2.048Mbps over two pairs at a distance up to 4.2Km Considering Sri Lanka, the widely used is ADSL – Asymmetric Digital Subscriber Line ADSL This technology takes advantage of the unused bandwidth that already exists on the phone line. Bandwidth refers to the amount of data that can be transmitted over a given time period. Essentially, the more bandwidth, the faster information can be delivered to the computer. The upstream (from the computer to the Internet) and the downstream (from the Internet to the computer) speeds are different hence the term 'asymmetric.' ADSL is perfect for receiving multimedia, audio, video and animation files in real time. ADSL technology gives users fast digital data transmission and does not affect the analog telephone service that is currently used. That means the user can enjoy a fast, permanent connection to the Internet, and still have full use of the telephone. At present the ADSL services are available in Sri Lanka through Sri Lanka Telecom (SLT) and Suntel. Refer appendix 2 for the tariff rates. The details were taken from the SLT City Office Kandy and Suntel City Office Kandy. Additionally, Dialog Telekom provides a broadband high-speed internet access. Given below are the details of dialog broadband. Dialog Broad band’s wide range of high speed solutions are designed to meet the needs of businesses of all sizes. All services offer full broadband speeds, ultra-reliable connectivity, business-class features, and high speed broadband internet access virtually anywhere in the Island. Island-wide infrastructure and international gateway, continuous traffic management and complete security are ensured both on the hosts as well as on the network. Adequate redundancy is provided for in the international circuit as well as in equipment. The IP backbone makes internet delivery possible to the client’s location without having to depend on a third party for access. The distinguishing feature of high speed internet services is via a satellite gateway and SEA-ME-WE fiber optic cable. Internet services give the equal measure of performance, reliability and flexibility and cost-effectiveness. Dialog Broadband Internet has in place rigorous traffic management and monitoring procedures. All nodes services and equipment are monitored online and online traffic graphs are guaranteed. Connectivity and services are monitored round-the-clock. Bandwidth manager software measures and allocates bandwidth to users for optimum usage. Real time fault ensures minimum downtime in case of a failure. Advantages of using ADSL at Aitken Spence It is always-on - the connection is always available without needing to wait for ages to 'dial up'. It also doesn't 'drop out'. It is 'just there' - when you need it, instantly. It is dramatically faster than a dial modem or ISDN connection - up to 30-50 times faster. This makes an enormous difference to the effectiveness of the internet experience, and as well for the company. ADSL seamlessly 'shares' a phone line along with normal 'voice' services. The phone is not engaged when using the internet - in fact the user can freely use the phone at the same time as access the internet. No second phone line needed. You can easily offset the costs of ADSL by Rs.3000 per month or more - this is the amount you might have otherwise spent on a second phone line and on local calls to access the internet with a modem, without interrupting the use of your primary telephone service. You can save time and frustration by never having to wait for a modem to connect, or suffering connection dropouts, in addition to the hugely increased download speeds available It is far more cost effective Limitations of ADSL ADSL is not available on all phone services Aitken Spence may not be able to get ADSL for many reasons but the most common are: o The company is too far from the local telephone exchange. o The local telephone exchange is not enabled. ADSL is not a guaranteed bandwidth service o For example the SLT network architecture, and the manner in which ADSL data is moved around the city, mean that network congestion is possible in the line at some times. The speeds quoted for ADSL services are theoretical maximum rates. o Performance of the network may vary by time of day or may decrease over time due to increased network interference which is evident by the SLT, Suntel line networks. ADSL is only fast in one direction o The asymmetric transfer rates provided by ADSL are designed to optimise the speed of internet downloads. As a consequence, the upload speed on ADSL is far slower. o This means that ADSL is often unsuitable for situations where you intend to upload (or serve) large quantities of data from a set location back out into the internet. Leased Line A leased line is a private high-performance circuit leased by a common carrier between a customer and a service provider’s network. Leased lines are mostly used for either internet access or used privately between two customer sites. Unlike a dial-up connection, a leased line is always active. Similarly unlike broadband, a leased line is not contended or shared and delivers dedicated guaranteed bandwidth straight to the internet backbone. Users pay a premium for a leased line and it is supported by a comprehensive Service-Level Agreement (SLA) with a guaranteed fix time and a compensation clause. Otherwise referred to as a point to point, private circuit, private line or dedicated access. Bandwidth can be tailored to the company's exact requirements, ranging from 64 Kbps to 1000 Mbps. The required speed could depend upon the number of employees accessing the internet or perhaps upon the applications used; some being more bandwidth intensive than others. Implementation of a Leased lines at Aitken Spence will cater for the following: Provide a scalable access method, important particularly for organizations with large user groups. The quality of the connection is far superior to what is normally available through dialup, thanks to digital signalling, less noise, fewer exchanges etc. Provide permanent connectivity to the Internet. Since the access is "always on", it is possible to associate a pool of permanent IP addresses with a particular leased line. Using these IP addresses it becomes possible to deploy a variety of services such as mail, FTP, WWW, DNS, and proxy, to name the most common requirements of Aitken Spence. Starting typically with 64 Kbps, it is possible to deploy a scalable architecture, with multiples of E1 (2 MBPS) pipes, providing the necessary bandwidth Leased line can provide Aitken Spence with the following: High availability and super fast access to web sites or mail servers hosted at the premises. Online transactions 24x7 to support the business. Higher service level performance than available by alternative connections (ADSL/SDSL etc.) In excess of 2Mbps Internet access to the offices Fast access to a secondary data centre site for business continuity applications. High bandwidth at a later date with the option to scale bandwidth rapidly as demand increases. Currently SLT and Dialog Telekom provide the leased line facility, given below are the details of the SLT leased lines and the Dialog leased lines. SLT Are dedicated digital circuits connecting two fixed points across a private network. They are in fact the most secure and reliable type of voice and data connections available today. Totally dedicated thus its exclusive to the user. Because no one else ever uses it, the core user has total access to it - 24 hours a day - meaning there's never a delay in sending information. SLT Leased Line is delivered on Copper or Faber optic transmission networks and is monitored around the clock to provide you with a highly reliable service. Dialog Leased Lines Dialog provides Leased Line Internet connectivity to any organization located in any part of the Island. High speed connectivity. Connected to the Internet backbone directly via Sea Me We 3 submarine cable. Redundancy Satellite link for emergency use. Fig 1.3 The figure 1.3 shows a typical leased line connection. Advantages of leased lines to Aitken Spence Secure and private - dedicated exclusively to the company Speed – symmetrical, un-contended and direct Reliable – private circuit local loops are a premium product supported by fast time to fix guarantees Resilience – redundancy can be incorporated to reduce outages Wide choice of speeds – bandwidth on demand, easily upgradeable Dependable - leased lines are suitable for in-house office web hosting Geographic reach - the performance you need across the globe Total security - your own dedicated connection Network Operations Centre (NOC) - 24x7x365 network monitoring, technical and field support Service guarantees - backed by comprehensive Service Level Agreements Disadvantages of leased lines at Aitken Spence. Leased lines can be expensive to install and rent Lead times can be as long as 65 working days Distance dependent to nearest point of presence. Frame Relay Consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. Typical Frame relay connections range from 56Kbps to 2Mbps. Frame relay puts data in variable-size units called "frames" and leaves any necessary error-correction (such as re-transmission of data) up to the endpoints. This speeds up overall data transmission. For most services, the network provides a permanent virtual circuit (PVC), which means that the customer sees a continuous, dedicated connection without having to pay for a full-time leased line, while the service-provider figures out the route each frame travels to its destination and can charge based on usage. Frame relay has its technical base in the packet-switching technology, designed for transmitting analog data such as voice conversations. Frame relay offers a fast packet technology, which means that the protocol does not attempt to correct errors. When a frame relay network detects an error in a frame, it simply drops that frame. The end points have the responsibility for detecting and retransmitting dropped frames. (However, digital networks offer an incidence of error extraordinarily small relative to that of analog networks.) Frame relay often serves to connect local area networks (LANs) with major backbones as well as on public wide-area networks (WANs) and also in private network environments with leased lines over T-1 lines. It requires a dedicated connection during the transmission period. Voice and video can be sent over a frame relay network, often providing significant cost savings with some sacrifice in voice or video quality, depending on network configuration. Frame Relay has become one of the most extensively-used WAN protocols. Its cheapness (compared to leased lines) provided one reason for its popularity. The extreme simplicity of configuring user equipment in a Frame Relay network offers another reason for Frame Relay's popularity. Why Aitken Spence Needs a Frame Relay Need for increased speed Dynamic Bandwidth requirements Smarter Attached Devices Higher performance Widespread Digital facilities At present, the Frame Relay is offered by SLT, Suntel, LankaCom in Sri Lanka. SLT The above description about the frame relay comply with the SLT’s technology LankaCom LankaCom provides international Frame Relay services with its own Frame Relay infrastructure using Cisco-Stratacom and New Bridge equipment. Suntel The frame relay backbone network of Suntel provides extensive island-wide coverage, which enables them to cost effectively deliver high quality, reliable and secure wide area networks (WAN), to the customers. Cost effective delivery of high quality, reliable and secure wide area networks (WAN) for enterprise connectivity is provided through Suntel’s frame relay switches, which are strategically located in order to facilitate island-wide coverage. Switch to switch interconnection is through multiple E1 channel configurations and every switch is connected to two other switches providing redundant data paths in case of link failures. This will enable them to provide the customer with enhanced bandwidth and efficient and reliable data communication networks. Advantages of Frame Relay to Aitken Spence. Supports multicasting Low cost compared to other technologies Exploits recent advances in technology The maximum burst permits data to transmit as fast as the circuit’s capacity. Frame Relay is also widely deployed Disadvantages of Frame Relay to Aitken Spence. Because Frame Relay is a packet-switched technology, latency (delay) is introduced in the processing of each packet at every Frame Relay switch. Difficulty in ensuring Quality of Service, this is due to the fact that Frame Relay uses variable-length packets. IPTV – Internet Protocol Television (Internet Protocol TV) also called "TV over IP," IPTV delivers scheduled TV programs and video-on-demand (VOD) via the IP protocol and digital streaming techniques used to watch video on the Internet. In order to receive and decode the images in real-time, the user requires either an IPTV set-top box or a computer and software-based media player. IPTV enables a data-voice-video "triple play" service to be based entirely on IP because Internet access, voice over IP (VoIP) and IPTV all use the same IP packet format. IP television service allows Aitken Spence to have more control of television services. This control ranges from instant service activation to real time television on demand controls. Some of the advanced Internet television features such as personal media channels, anywhere television extensions, global television channels and multimedia programs are described. Because each IP television viewer has a unique address, this allows advertising messages to be sent to specific viewers (addressable advertising). The ability to direct advertising messages to specific target audiences is more valuable to companies than traditional broadcast advertising and this may result in reduced viewing costs. Advantages of using IPTV at Aitken Spence. Includes the ability to integrate television with other IP-based services like high speed Internet access and VoIP. A switched IP network also allows for the delivery of significantly more content and functionality. A switched IP network works differently. Content remains in the network, and only the content the customer selects is sent into the company/hotel. That frees up bandwidth, this also implicates that the Aitken Spence’s privacy could be compromised to a greater extent than is possible with traditional TV or satellite networks. Limitations of using IPTV at Aitken Spence Because IPTV is based on the Internet Protocol, it is sensitive to packet loss and delays if the IPTV connection is not fast enough. Note: At the moment IPTV is not available in Sri Lanka, but SLT is planning to launch IPTV to broadcast video on demand in the future. VoIP – Voice over Internet Protocol VoIP is the routing of voice conversations over the Internet or through any other IP-based network. Companies providing VoIP service are commonly referred to as providers, and protocols which are used to carry voice signals over the IP network are commonly referred to as Voice over IP or VoIP protocols. Advantages of using VoIP at Aitken Spence VoIP services that use regular telephones can generally make calls to any regular phone and receive calls from any phone. VoIP saves money spent on long distance phone calls while promoting bandwidth data capacity and telephony efficiency. By using a phone adaptor (ATA), the VoIP technology can travel anywhere where the user can connect to a broadband connection. Disadvantages of using VoIP at Aitken Spence. Because User Datagram Protocol does not provide a mechanism to ensure that data packets are delivered in sequential order, or provide Quality of Service guarantees, VoIP implementations face problems dealing with latency and jitter. The support of sending faxes over VoIP is still limited. The existing voice codecs are not designed for fax transmission. The nature of IP makes it difficult to locate network users geographically. Emergency calls, therefore, cannot easily be routed to a nearby call center, and are impossible on some VoIP systems. The majority of consumer VoIP solutions do not support encryption yet. As a result, it is relatively easy to eavesdrop on VoIP calls and even change their content. The figure below shows the overview of a VOIP Fig 1.4 Some VOIP Providers in Sri Lanka Omega Technologies (Pvt) Ltd. TruConnect Technologies (Pvt) Ltd. IP VPN – Internet Protocol Virtual Private Network Virtual Private Network (VPN) delivers private network services over a public infrastructure. An IP VPN is a partitioned private network constructed over a shared IP-based backbone that utilizes technologies to ensure privacy of data. They offer enterprise-class scalability and reach-ability across multiple IP-based infrastructures, along with many of the performance and security characteristics traditionally found only in dedicated private environments. MPLS (Multi Protocol Label Switching) technology based VPNs combines the intelligence of private IP routing with the added performance of label switching to move packets between any locations on the network. With only one access link to the MPLS “cloud” from each of the locations, full mesh connectivity will improve the network scalability, reliability, and internal network application performance. IP VPN is provided by the SLT, Dialog Telekom and Suntel. Given below are the descriptions of each IP VPN services provided by the aforementioned companies. Suntel IP VPN Suntel’s IP VPN network is powered by CISCO and built using MPLS (Multi Protocol Label Switching) which can provide virtual networks for different customers in such a manner that that external party cannot penetrate into the VPN. Cisco is the world leader in supplying technology and their systems are modular and scalable for small to very large enterprises. Suntel customers will benefit by reduced cost of communication infrastructure, increased reliability and security, easy connectivity to remote workers, improved communication within groups, site to site connectivity for branch offices and the opportunity to broaden their geographic presence. With Suntel’s IP VPN facility, customers will no longer require skilled technical staff to manage the network at their end. Suntel will provide that service through IP VPN, making connectivity between branch offices far better and smoother. Dialog Telekom IP VPN MPLS based IP VPN solution capitalizes on the investment in Dialog’s Advance network and leverages the strengths of the metro area networking capabilities to provide operational cost savings to the customers with legacy Fast Packet or Private Line networks, while evolving into an IP infrastructure. IP-VPN Service also provides the platform that customers need to add other value added services over time such as IP Telephony, Network-based Firewalls and Internet Offload capabilities. Customers in and out of the traditional Dialog Broadband footprint that need a high-performance, cost-effective network solution, which offers end-to-end, fully meshed, any-to-any connectivity (via ATM, FR and Ethernet) on an MPLS platform as shown in fig 1.5. Multiprotocol Backbone of Dialog offer Reduce network management cost and complexity while rapidly scaling to deploy business applications to new locations. Secure, scalable and shared facilities to reduce the investment of building private enterprise networks. Exceeds the Quality of Service and privacy of ATM and Frame networks. Fig 1.5 Sri Lanka Telecom IP VPN SLT IP VPN as shown in the figure below gives the user choices in the network design of sophisticated VPN technologies, access, security and voice, with the flexibility to add on options such as remote access and hosting in IDC (Internet Data Centre). Fig 1.6 Ways in which IP VPN can benefit the Aitken Spence. Intranet IP VPNs can create an intranet that links a corporate headquarters to remote offices over a shared network allowing users to gain access to secured corporate information Extranets Extranets support business-to-business communications enabling an enterprise to be connected with other enterprises, customers, suppliers or business partners. Cost Effectiveness Previously, network connections between sites required dedicated circuits or private virtual circuits (PVCs). MPLS-based VPNs provide access to the entire IP network with any-to-any connectivity. This will reduce connectivity charges due to the sharing of infrastructure. Reliability Network redundancy and fault-tolerance ensure service availability. Convergence IP VPN provides seamless integration of voice and data networks under one IP network infrastructure, with the ability to customize VPN services for each business customer thereby increasing differentiation and adding value through bundled services for data, voice, video, network security and other options. Security Each VPN on a single physical infrastructure is treated as a logically independent routing domain, allowing end-users to use private and unregistered IP addresses to secure their data as it travels through your network. Scalability MPLS-based network architecture easily adapts to growth in complexity and volume. Since the VPN network is any-to-any by default, VPN network expansion can be achieved with minimum additional expenses . Flexibility VPNs can be developed with different applications such as Full-Mesh topology for voice and Hub-and-Spoke for Internet access. Class of service IP VPNs incorporate the ability to provide advanced Class of Service (CoS) features that ensures network priority for mission-critical traffic, allowing businesses to choose the appropriate CoS for their specific traffic patterns and business requirements. IP VPN services offered by SLT VPN with Classes of Service - SLT provides Classes of features for providing prioritization for traffic. VPN with Integrated Internet Access - VPN can be given integrated internet access, rather than having a separate internet leased line. Remote VPN Access - Provide remote workers or travelling users the same level of connectivity as individuals who work in branch offices VPN with ISDN Backup - ISDN Backup provides redundancy to the VPN site. Advantages of IP VPN to Aitken Spence Cost effectiveness - Cost savings are a great motivator for enterprises adopting IP VPN's in today's economic environment. Previously, network connections between sites required a dedicated circuit or private virtual circuit (PVC). IP networks provide access to the entire IP network for one site for one price - with reduced connectivity charges due to the sharing of infrastructure. Mobile or remote users can be migrated to an IP network from private dial-up networks that are otherwise cumbersome and costly to maintain. Reduced total cost of ownership - With IP VPN's one can buy capacity on the public Internet, and isolate the traffic using network-based security to create the IP VPN. This reduces the costs because the user doesn’t need to over specify the network to ensure capacity. Nor does the user have the capital or revenue costs associated with maintaining and developing a private network, as these costs are shared with all users of the public network. Improved security - When the IP VPN is created, the user separates the traffic by encrypting it. This secures the data against unauthorised third party access or manipulation. Such intrusions are very difficult to detect even on a private-circuit-based (rather than IP VPN) network. This level of security also allows the user to control site access on a user-by-user basis. Ease of extending private networks to remote locations - Using a VPN on a mixture of networks may be the only feasible way to provision services, particularly where budgets are limited. Effective platform for web-enabled back-office applications - Aitken Spence is increasingly adopting applications that make heavy demands on bandwidth, as they have been designed for Internet-like networks. IP applications like dial-in for remote access, video-over-IP, IP telephony, and audio- or videoconferencing can easily be bundled on top of basic IP VPN solutions. Speed of implementation - In contrast to the establishment of the companies own wide area network (WAN), most of the infrastructure for an IP VPN is already in place. This enables rapid deployment and flexible development. Disadvantages of IP VPN to Aitken Spence Standards/Interoperability - although IPSEC is the IETF standard protocol for IP VPNs, many companies (such as Microsoft) do not support it. As a result, the same equipment must be used at both ends of the tunnel to ensure interoperability. IPSEC is difficult to set-up and manage - remote clients need to be configured with the right security parameters. All traffic over the VPN is encrypted, regardless of need. This can potentially cause bottlenecks since encrypting data creates network overhead. Provides no internal protection on the corporate network - the VPN endpoint is typically at the edge of the network. Once employees are on the internal corporate network, data is not longer encrypted. IP VPNs cannot restrict employees from accessing any server on the internal network freely. Evaluation of the Communication Technologies. Technology Performance ADSL – Accessing Corporate Download Intranets 2048kbps Downloading large Upload Files and / or 512 kbps Attachments Online shopping and e-commerce applications Web browsing at a faster speed online ISDN – 64Kbps It is the Global Standard for high speed voice, data and video communications ISDN also equips for faster Internet surfing, G4 faxes Provides a static bandwidth. Advantages Access to the Internet, phone and fax on the same line increases business Un-metered Internet access makes budgeting easier No extra telephone charge. Limitations Bandwidth dynamic Not available in all the physical location Provides a very low BER You get Instant Call Connection, Perfect Clarity, Reliability and Speed. It is easy to use. Fast internet access throughput can be as much as 128 Kbps Fast file transfer Video conferencing Remote network access Not ready always Dialup access Not available in all the physical location Not suitable to mobile users. Technology LEASED LINE – 256kbps to 1Gps Performance Online transactions 24x7 to support the business model In excess of 2Mbps Internet access to their offices Fast access to a secondary data centre site for business continuity applications Permanent IP address Dedicated bandwidth Advantages Limitations Geographic reach - the Very expensive performance you need Professional's across the globe maintenance Flexibility - scalable options from 2 Mbps to STM-16 Total security - your own dedicated connection Advanced infrastructure optimum service quality and reliability Technology FRAME RELAY – 64Kbps to 2Mbps Performance Provides a permanent virtual circuit (PVC). Use packet-switching technology Voice and video can be sent over a frame relay network Advantages Limitations Lower cost of ownership Latency is introduced Low overhead combined with high reliability Difficulty in ensuring Quality Network scalability, of Service flexibility and disaster recovery Inter-working with other new services and applications. Reduces the necessity of installing multiple modems and other equipments. IP VPN MPLS (Multi Protocol Label Switching) technology based VPNs combines the intelligence of private IP routing with the added performance of label switching. Cost Effectiveness Convergence IP VPNs incorporate the ability to provide advanced Class of Service (CoS) features Provides no internal protection on the corporate network. All traffic is encrypted causing bottlenecks. Difficult to set up and maintain Recommendation Considering the above evaluation of the available telecommunication technologies in Sri Lanka and the history of the providers, which are SLT, Suntel, Dialog Telekom and LankaCom. I strongly recommend the usage of Frame Relay (2Mbps) network from Sri Lanka Telecom to be implemented at Aitken Spence. With the Frame Relay, data transfers among the Group’s various locations can take place and also the same network can be used for corporate voice, which will result in securing huge savings on toll by pass. With this technology the following operations can be conducted successfully. Reservation Billing Payment Stock and supplies Human resource management Advertisement Customer relations management. The reason for getting the service from SLT is because they are a renowned Telco and thus will provide the best service. They will provide “around the clock” services ensuring only the best to the customer. Few reasons for choosing SLT Frame Relay Lower cost of ownership Well established and widely adopted standards that allow open architecture and plug and play service implementation Low overhead combined with high reliability Network scalability, flexibility and disaster recovery Inter-working with other new services and applications such as ATM Alternative If Aitken Spence is to outsource its business entities outside Sri Lanka they can opt for an IP VPN from SLT to connect to the international branches and use the existing Frame Relay for the local ventures. This will be a big boost for the services As a backup line, if the frame relay network fails, I recommend the usage of an ISDN. The ISDN service can be taken from the SLT and this will run as a back up line in alternate to the current frame relay.