Browsing by Author "Dias, PGV"

Now showing 1 - 4 of 4

item: Thesis-Abstract
Design and implementation of a network traffic analyzing utility
Pushpa, KP; Dias, PGV
Developments in Information and Communication Technology (lCT) have created many new applications, which require a large amount of Internet bandwidth for proper application usage. However, Internet bandwidth is an expensive resource especially in this part of the world. Therefore, enterprises that use the Internet for business always need to efficiently use the bandwidth. Internet Service Providers may also need to manage their Internet bandwidth efficiently in order to increase the profit margin of their services. Knowing the current (and past) usage is an important requirement in estimating the bandwidth requirement of a corporate network. The information about the composition of the use of the bandwidth by applications, user groups, etc. will help an administrator to efficiently manage it. Furthermore, knowing what is happening in the network always helps an administrator to keep the network secure, efficient and reliable all the time. We studied the requirements of a network administrator by considering LEARN as a test bed for this study. We then assessed, whether the existing network traffic monitoring tools can provide the required information to the administrator. We examined some of the popular network monitoring tools that are widely used in the Internet community for their features and drawbacks. We found that the existing tools for network traffic monitoring are not capable of providing most of the required information by the administrator. With these results, we identified the features available in those tools, and developed a new tool, LEARNStat, re-using some of the freeware utilities available in order to meet the requirements of a network administrator. We tested LEARNStat in LEARN which is our test-bed, and during the short period of running LEARNStat, we were able to obtain several important results. In this thesis, we discuss the requirements of a network administrator and how we met those with LEARNStat. We present a brief description of related principles and also discuss the results we obtained with LEARNStat. The thesis also includes possible future enhancements for the LEARNStat.
item: Conference-Abstract
Multimedia Message Distribution in a Constrained Environment
Fernando, MSD; Wijesoma, WS; Dias, PGV
Currently there are standards governing message handling, in particular MIME (Multipurpose Internet Mail Extensions)[1,2], for telecommuting mail messages encompassing a multitude of media, such as graphics images, voice data and motion video apart from plain text. However, the MIME standard (and also work in progress[3]) presupposes certain minimum technical capabilities amongst interconnected and participating mailservers for distribution of such multimedia mail. In particular, the interconnecting channels between mailservers should be of sufficient bandwidth to conduct the large amount of data in MIME messages at 'reasonable' rates and also the nodes must have adequate storage capacity for same. This requirement for bandwidth of channels and storage of mailservers for MIME capability prevents users connected to 'underprivileged'mail nodes from enjoying the benefits brought about by multi-media information and messaging. This may be in spite of the end users owning or having access to resource rich machines.In this paper a smart approach to routing of multimedia messages in an internetwork of mailservers, disparate in storage capacity, performance and network bandwidth, is presented.
item: Thesis-Abstract
On-The-Fly inter-proxy data compression for web access
Gurusinghe, PSK; Dias, PGV
There has been a significant growth in the residential apartment market in Sri Lanka during the last decade. The main reasons behind this upsurge include the growth of population, changes in living patterns and the soaring prices of property particularly Obtaining a reasonable speed for web access is a problem in many areas, especially for small organizations such as schools, dial-up, and mobile users, due to the low bandwidth of the available links. One solution, which is supported by HTTP 1.1, is the compression of web pages, but this needs support by both the web server and web client. As most web servers have not enabled such support, this feature is in limited use. An alternative option is to implement compression between two proxy servers located at each end of the bandwidth-limited link. This dissertation describes the implementation of such a system. A compression scheme was implemented which is transparent to both client and server. Data is compressed at the upstream proxy server of the bandwidth-limited link, and de-compressed at the downstream proxy server of the link. Different types of content are identified based on the content-type HTTP header and different compressors are used on each content-type. HTTP headers and text content-types (html, css, txt etc.) are highly compressible. A number of text compression schemes were evaluated, and, gzip was selected as the compressor for such content. A unique feature of our system is the use of a pre-set dictionary for HTTP header compression, which enabled us to get very good compression ratios. Although jpeg images are already in a compressed format, they can generally be further compressed without excessively degrading the perceived image quality. We do so whenever feasible. Persistent connections over the limited bandwidth links were introduced to eliminate the delay caused by TCP connection establishment. The performance of .the system under different workloads was analyzed, which showed that the system provides a significant improvement in response time over a low-speed connection.
item: Thesis-Abstract
Web based domain registration and payment system for the LK domain registry
Amarasiri, R.; Dias, PGV
This research developed and evaluated the different aspects such as security, feasibility, etc. of an online domain registration system and a payment gateway for the Sri Lanka Domain Registry as a pilot project in establishing a secure e-commerce infrastructure in Sri Lanka. In doing so, it was able to formalize and stream line the procedures and guidelines of registering domains and eliminate the delays that were earlier involved in registering domains at the registry. The Internet today has become a place for people to do their day to day purchases as well as for the sale of products to a global market. The security of the information that is being exchanged in such transactions is vital. If the correct methodologies are not used, it could lead to losses to the consumers as well as heavy losses to vendors that could include damage to long built reputation. Although the Internet usage in Sri Lanka has risen dramatically since its introduction in 1995, local institutions have still not fully exploited its potential for reaching a global market, the main factor for this is the unavailability of a good secure online payment infrastructure in Sri Lanka. Currency regulations restrict people from using the facilities offered by such infrastructure in other countries. Many of the financial institutions in Sri Lanka are reluctant to offer such facilities because of the fear of fraudulent transactions raised by the myth that submitting sensitive information such as credit card numbers on the Internet is very insecure. As a results of the research a web based registration system was developed and implemented to handle the domain registration process and a set of guidelines were also developed to assist in the acceptance of domain names. The security of the domain registry's servers was also scrutinized to enable smooth operations of the registry. Recommendations on selecting a suitable online payment system were also made by evaluating the implementation of different mechanisms.