Optimalisasi Keamanan Jaringan Menggunakan Metode Port Knocking Pada LAZIS Wahdah Jakarta

Abstract— Network security system is very important, because it relates to the security of resources in network, if the networksecurity system is weak, so people are not interested could be easy to attacks on the system, either to manipulate the data or changing the configuration of the network . In Lazis Wahdah has not made the block on port network systems, and used of modem Asymmetric Digital Subscriber Line (ADSL) in the network do not block the port. This is because the ADSL Modem just can do simple configuration and also not have features such as Router. Focusing on the issue, the use of methods Port Knocking on Mikrotik RB951UI-2ND is an appropriate way to improve network security system. With Port Knocking only IP address that corresponds to the rule or according to a predetermined Knock can access Mikrotik, while that does not comply with the rule will remain blocked. So Port Knockingmethod can improve the security system on the network at Lazis Wahdah Jakarta. Intisari— Keamanan sistem jaringan sangat penting, karena berkaitan dengan keamanan sumber daya yang ada padajaringan berupa data-data, jika system keamanan jaringan lemah,maka orang yang tidak berkepentingan dapat denganmudah melakukan serangan pada sistem tersebut, baik untuk melakukan manipulasi data atau merubah konfigurasi padajaringan. Di Lazis Wahdah Jakarta belum melakukan blok pada port system jaringan, dan penggunaan modem AsymmetricDigital Subscriber Line (ADSL) pada jaringaan tidak melakukan blok terhadap port, ini karena Modem ADSL hanya bisamelakukan konfigurasi sederhana dan juga tidak memilik ifitur seperti halnya Router. Berfokus pada masalah tersebut,penggunaan metode Port Knocking pada Mikrotik RB941-2ND merupakan cara yang tepat untuk meningkatkan sistemkeamanan jaringan. Dengan Port Knocking hanya IP Address yang sesuai dengan rule atau sesuai dengan Knock yang telahditentukan yang dapat mengakses ke Mikrotik, sementara yang tidak sesuai dengan rule akan tetap diblok. Sehingga metodePort Knocking dapat meningkatkan system keamanan pada jaringan Lazis Wahdah Jakarta.

Determining of Optimal Telemedicine Communication Technologies with Regards to Network Interactive Modes: A Delphi Survey

Introduction: Different communication services with varying bandwidth are used to send information in the form of telemedicine technology. Bandwidth management, as defined in telemedicine technology, refers to using the desirable communication services according to the type of transaction and the information size to be transferred. Selection of communication services must be in such a way to result in minimum latency in the process of sending information and maintaining maximum cost-effectiveness.Material and Methods: This is an applied research which was conducted in 2019 by questionnaire survey amongst 60 participants, specialized in health information technology and medical informatics, who are working in hospitals and educational institutions of Tehran. Likert rating scale was used to quantify the research questions. Finally, by analyzing each weighted average, this study revealed the desirable communication services that correspond to the required transactions for deployment of telemedicine.Results: Transfer of multimedia information, using synchronized teleconferencing via primary low bandwidth technologies, had the lowest number average (0.96) and transmission of hybrid data (combination of picture, text, multimedia templates in synchronized or asynchronized modes) via Asymmetric Digital Subscriber Line (ADSL) technology had the highest average (4.96).Conclusion: Selection of communication services, with regard to its convergence with the information size and the type of their application, plays a significant role in controlling network traffic and preventing latency in the process of sending information in the context of telemedicine technology. High bandwidth communication services should be used for those telemedicine systems, which are offering services to many users, as well as those in which real-time transmission of information is essential. It needs to be pointed out that with regard to the cost-effectiveness of sending information, it is necessary to use low-cost services with low bandwidth for transfer of light weight information as well as for asynchronous applications in which latency in the process of information transfer is not detrimental.

A Hybrid Method to Reduce PAPR of OFDM to Support 5G Technology

The orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation scheme used for the transfer of multimedia data. Well-known systems like ADSL (asymmetric digital subscriber line) internet, wireless local area networks (LANs), long-term evolution (LTE), and 5G technologies use OFDM. The major limitation of OFDM is the high peak-to-average power ratio (PAPR). High PAPR lowers the power efficiency, thus impeding the implementation of OFDM. The PAPR problem is more significant in an uplink. A high peak-to-average power ratio (PAPR) occurs due to large envelope fluctuations in OFDM signal and requires a highly linear high-power amplifier (HPA). Power amplifiers with a large linear range are expensive, bulky, and difficult to manufacture. In order to reduce the PAPR, a hybrid technique is proposed in this chapter with repeated clipping and filtering (RCF) and precoding techniques. The proposed method is improving the PAPR as well as BER. Five types of pre-coding techniques are used and then compared with each other.

Analisis Pengaruh Reduksi Peak to Average Power Ratio (PAPR) dengan Teknik Selected Mapping (SLM) Terhadap Efisiensi Spektrum pada Sistem OFDM

Teknologi Orthogonal Frequency Division Multiplexing (OFDM) telah banyak diimplementasikan dalam komunikasi digital berkecepatan tinggi seperti Wireless Local Area Network (WLAN), Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), dan Asymmetric Digital Subscriber Line (ADSL). Salah satu kelemahan dari sistem OFDM adalah tingginya nilai Peak to Average Power Ratio (PAPR) yang menyebabkan terjadinya distorsi non linier pada High Power Amplifier (HPA). Akibatnya, terjadi penurunan efisiensi spektrum. Teknik reduksi PAPR yang digunakan pada karya tulis ini adalah teknik Selected Mapping (SLM) dan SLM Riemann. Hasil simulasi digambarkan dengan kurva Cumulative Complementary Distribution Function (CCDF) dan kurva efisiensi spektrum. Parameter yang digunakan yaitu jumlah subblok dan jumlah subcarrier. Pada penelitian ini, teknik SLM menghasilkan nilai PAPR sebesar 8.912 dB sedangkan teknik SLM Riemann menghasilkan nilai PAPR sebesar 9.099 dB. Sehingga teknik SLM dapat mereduksi nilai PAPR lebih baik dibandingkan dengan teknik SLM Riemann. Perbedaan jumlah subblok juga mempengaruhi kinerja teknik reduksi, teknik SLM dengan subblok 8 menghasilkan kinerja 0.5 dB lebih baik dibandingkan subblok 4. Sehingga kinerja akan semakin baik apabila jumlah subblok yang digunakan semakin banyak. Kemudian semakin banyak jumlah subcarrier maka nilai PAPR yang dihasilkan akan semakin besar. Selanjutnya, efisiensi spektrum meningkat seiring bertambahnya daya transmit. Teknik reduksi SLM dan SLM Riemann mampu meningkatkan daya transmit yang juga menyebabkan meningkatnya efisiensi spektrum. Penggunaan jumlah subblok yang lebih banyak akan meningkatkan efisiensi spektrum. Teknik SLM dengan subblok 4 menghasilkan efisiensi spektrum sebesar 0.425 bit/s/Hz dan subblok 8 menghasilkan efisiensi spektrum sebesar 0.444 bit/s/Hz. Teknik reduksi SLM memberikan hasil efisiensi spektrum yang lebih baik dari teknik reduksi SLM Riemann.

Performance Evaluation of Interactive Video Streaming over WiMAX Network

Nowadays, the desire of internet access and the need of digital encodings have influenced quite a large number of users to access high quality video application. Offering multimedia services not only to the wired but to wireless mobile client is becoming more viable. In wireless medium, video-streaming still has high resource requirements, for example, bandwidth, traffic priority, smooth play-backs. Therefore, bandwidth demands of these applications are far exceeding the capacity of 3G and Wireless Local Area Networks (LANs). The current research demonstrates the introductory understanding of the Worldwide Interoperability for Microwave Access (WiMax) network, applications, the mechanisms, its potential features, and techniques used to provide QoS in WiMAX, and lastly the network is simulated to report the diverse requirements of streamed video conferencing traffic and its specifications. For this purpose two input parameters of video traffic are selected, i.e, refresh rate, which is monitored in terms of frames per second and pixel resolutions which basically counts the number of pixels in digital imaging. The network model is developed in OPNET. Different outcomes from simulation based models are analyzed and appropriate reasons are also discussed. Apart from this, the second aim of the current research is to address whether WiMAX access technology for streaming video applications could provide comparable network performance to Asymmetric Digital Subscriber Line (ADSL). For this purpose network metrices such as End to End delay and throughput is taken into consideration for optimization.

VISUALISASI SISTEM ASYMMETRIC DIGITAL SUBSCRIBER LINE (ADSL) DENGAN MENGGUNAKAN MODULASI QUADRATURE PHASE SHIFT KEYING (QPSK)

Sistem Asymmetric Digital Subscriber Line (ADSL) merupakan teknologi akses yang memungkinkan terjadinya komunikasi data, suara dan video secara bersamaan pada media akses tembaga. Komunikasi data tidak dapat dihindarkan dari adanya derau, tidak terkecuali sistem ADSL yang mengalami kesalahan dalam hal pengiriman yang disebabkan adanya derau sehingga membuat nilai bit error rate (BER) meningkat. Oleh karena itu, diperlukan cara untuk mengurangi derau sehingga dapat memperkecil nilai BER. Untuk mengurangi derau dan mendapatkan nilai BER maka diperlukan metode modulasi Quadrature phase shift keying (QPSK) pada sistem ADSL. Visualisasi sistem dibutuhkan untuk mengetahui kinerja dari sistem ADSL dan mengetahui BER yang di timbulkan. Dari hasil visualisasi dengan memberikan masukan data 64 bit, menampilkan konstelasi yang mengalami penyebaran data tetapi tidak merusak bentuk dari konstelasi. Ketika konstelasi masuk ke kanal Additif White Gaussian Noise (AWGN) dengan simpangan antara 0 dB – 20 dB dan interval 2 dB, dihasilkan nilai BER 0.3906 pada saat Signal to Noise Ratio (SNR) bernilai 0 dB sampai akhirnya BER bernilai nol pada saat SNR berkisar antara 9 dB - 20 dB.

On automated test system for asymmetric digital subscriber line equipment

The requirement for an automated test system has immensely increased due to the realization that manual testing is associated with additional resources and staffing constraints. In order to achieve a competitive edge, reduced development cost, timely product delivery, and product quality are mandatory in today's organization. Manual testing requires skilled operators that increase cost, time, and product delivery. The low cost computer-based automated system helps to get an edge by fulfilling these organizational demands. In this paper, an automated testing system has been developed to support functional testing of all phases of Nortel Networks 1-Meg modem system as its system under test (SUT). The modem is an inherently complex asymmetric digital subscriber line (ADSL) product and its testing is far more complex than just verification of process faults. The complexity of ADSL system renders automated test system an important and imperative part of ADSL testing. The subject paper demonstrates the indispensable need of automated test system for ADSL testing and its relative advantages in providing some benefit for the organization.

The Comparison between WLAN and Femtocell

The communication link of femtocell may be one of Wide Area Network (WAN) technologies, such as, Asymmetric Digital Subscriber Line (ADSL). Femtocell used a public network to establish connectivity between femtocell and core network elements where there are a set of challenges to the operators. However, femtocells use IP Network as a backhaul architecture instead of conventional cellular network infrastructure, so that Femtocells and WiFi infrastructure networks can come to a compromise as they have a lot of common iterative and inter-related technologies and activities. This raises the question as to whether femtocell technology will substitute the existing WiFi technology. By carefully analyzing the similarities and differences between the two technologies one can find this answer. This chapter provides a technical comparison between Femtocells and WiFi in terms of architecture, operation, and standards.

UBL: IMPLANTAÇÃO E RESULTADOS DO PROJETO INTERNET ULTRA BANDA LARGA OI MG

Este artigo apresenta um estudo sobre o projeto UBL (Ultra Banda Larga) da Oi em Belo Horizonte e nas suas cidades vizinhas. Trata-se de um projeto para up-grade das velocidades do Velox (produto de internet banda larga da empresa). O objetivo do trabalho é primeiramente apresentar uma introdução ao conceito de internet e tecnologia ADSL (Asymmetric, Digital Subscriber Line); descrever a execução do projeto UBL; apresentar alguns equipamentos básicos; detalhar a implantação do projeto e analisar a eficiência do projeto. Com os dados apresentados, foi possível identificar os ganhos obtidos com a implantação do projeto, como vantagens e facilidades operacionais e o número de portas disponibilizadas para o mercado.

Asymmetric Digital Subscriber Line

The plain, old telephone system (POTS) has formed the backbone of the communications world since its inception in the 1880s. Running on twisted pairs of copper wires bundled together, there has not really been any seminal developments in its mode of transmission, save for its transition from analogue to digital toward the end of the 1970s.