VoIP Servers Research Articles

Comparative Analysis of Voice Quality on iLBC and Speex Codecs Server PBX with Voice Comparison Method

VoIP servers provide several types of codecs including iLBC and Speex codecs, each type of codec has a different capacity and quality- different. So that in the process of choosing a codec implementation, VoIP becomes one of the things that affect the quality of communication. The iLBC and Speex codecs are intended for high quality but bitrate . By comparing iLBC and Speex communication, VoIP hoped that the better performance between the two codecs would communicate VoIP based on Quality of Service (QoS) and analyze the audio results of VoIP for voice quality analysis using the voice comparison method using Matlab. Based on the results of the research between the iLBC and Speex parameter value QoS including delay codec speex is smaller than iLBC codec of 31.12 ms. The jitter value of the iLBC and speex is the same, namely 0.01. The packet loss value of the iLBC codec is smaller than the speex codec of 6.18%. The results of the sound quality test in matlab using the sound comparison method showed that the delta amplitude codec speex value was smaller than iLBC codec of 0.00004551 volts.

Pengembangan Sistem VOIP Menggunakan Server Issabel Versi 4.0 dan Tunnel EOIP pada OMNI Hospital Alam Sutera

The VoIP communication system at OMNI Hospital Alam Sutera uses the Elastix 2.5 server with the Centos 5.11 operating system. Elastix 2.5 by the developer has been declared End of Life. The server security system is a serious concern considering that VoIP servers can be accessed from the internet. Iptables and fail2ban applications are applications that are used to limit and counteract those who try to attack the VoIP server. One application that can be used as an open source VoIP server is the Issabel Application version 4.0. The migration process from Elastix 2.5 application to Issabel 4.0 by backing up all configurations in the Elastix 2.5 application through a web browser including the configuration of endpoints, fax, e-mail, asterisk. After the backup file is downloaded then upload the backup file to the Issabel 4.0 application then run the migration process. Adding a backup path as a failover connection is needed because the VoIP communication protocol between the OMNI Hospitals Group still uses one path so that when there is a problem in the connection path, the communication protocol will stop. The tunnel EoIP is a protocol used as a backup path between the OMNI Hospitals Group site.

Membangun Server Portable untuk VoIP dan Web Server di Linux Ubuntu

Server is a computer that serves a particular task in the network which can be used by other computers. The server damage will cause some losses in various parties who use the server services. Losses can be in the form of financial or others. The server damage can also be caused by natural disasters, such as earthquakes, floods, landslides and others. Therefore, it is necessary to create a portable server for VoIP and web server. VoIP servers are built by using asterisk as well as using the zoiper app and 3CX Phone to run VoIP. Meanwhile, the web server is created by using sentora panel. sentora panel is used because it has an installed packet like apache, php, mysql, phpmyadmin and other supporting software, hence it does not need to install it one by one. This portable server can be taken anywhere and can also be used in various PC or Laptop. So when the natural disaster occurs, the server stay safe, and ready to use.

Forensic Analysis of Asterisk-FreePBX based VoIP Server

VoIP – Voice over IP is becoming an important aspect of communication. With invention of high speed Internet together with mobile phones has made it possible to utilize this highly important technology for voice communication. International calls are now possible with VoIP at compatible rates compared to past. The trend made people develop applications based on VoIP not only for private IP PBX but for subscribed users from all over the world. The dependency in whole technology is its VoIP Server, which is not directly exposed to end users, but if can be compromsed then can affect all the connected users. Looking at increasing popularity of VoIP, attackers are now targeting these VoIP servers for various purposes like stealing information or using service to make free calls. It is always difficult to prevent such attacks but investigation may always help in solving such attacks and preventing future attacks with similar modus operandi. These work focuses on forensic analysis of VoIP server asterisk and discusses important artifacts which can be retrieved from affected VoIP server.

Traffic Analysis over a VoIP Server

This paper describes a traffic study over a VoIP server. The aim is to perform a study to know the traffic of communications of the current system installed and so what is the bandwidth needed to replace the existing traditional phone system for a new IP telephony system. After this study we used a simulator to know which is the maximum traffic supported by the VoIP server, to know if the system can support all users connected. Finally there will be a study to know what the bandwidth needed to establish a link between two VoIP servers located at two sites separated by a distance of 3 Km.

M2KMIX: Identifying the Type of High Rate Flooding Attacks using a Mixture of Expert Systems

High rate flooding attacks such as SYN flood, UDP flood, and HTTP flood have been posing a perilous threat to Web servers, DNS servers, Mail servers, VoIP servers, etc. These high rate flooding attacks deplete the limited capacity of the server resources. Hence, there is a need for the protection of these critical resources from high rate flooding attacks. Existing detection techniques used in Firewalls, IPS, IDS, etc., fail to identify the illegitimate traffic due to its self-similarity nature of legitimate traffic and suffer from low detection accuracy and high false alarms. Also, very few in the literature have focused on identifying the type of attack. This paper focuses on the identification of type of high rate flooding attack with High detection accuracy and fewer false alarms. The attack type identification is achieved by training the classifiers with different feature subsets. Therefore, each trained classifier is an expert in different feature space. High detection accuracy is achieved by creating a mixture of expert classifiers and the ensemble output decisions are identified by our proposed Preferential Agreement (PA) rule. Our proposed classification algorithm, M2KMix (mixture of two Multi Layer Perceptron and one K-Nearest Neighbor models) differs from the existing solutions in feature selection, error cost reduction, and attack type identification. M2KMix was trained and tested with our own SSE Lab 2011 dataset and CAIDA dataset. Detection accuracy and False Alarms are the two metrics used to analyze the performance of the proposed M2KMix algorithm with the existing output combination methods such as mean, maximum, minimum, and product. From the simulation results, it is evident that M2KMix algorithm achieves high detection accuracy (97.8%) with fewer false alarms than the existing output combination methods. M2KMix identifies three types of flooding attacks, viz., the SYN Flood, UDP flood, and HTTP Flood, effectively with detection accuracy of 100%, 93.75%, and 97.5%, respectively.

Denial of service attacks targeting a SIP VoIP infrastructure: attack scenarios and prevention mechanisms

In this article we address the issue of denial of service attacks targeting the hardware and software of voice over IP servers or by misusing specific signaling protocol features. As a signaling protocol we investigate here the session initiation protocol. In this context we mainly identify attacks based on exhaustion of the memory of VoIP servers, or attacks that incur high CPU load. We deliver an overview of different attack possibilities and explain some attacks in more detail, including attacks utilizing the DNS system and those targeting the parser. A major conclusion of the work is the knowledge that SIP provides a wide range of features that can be used to mount DoS attacks. Discovering these attacks is inherently difficult, as is the case with DoS attacks on other IP components. However, with adequate server design, efficient implementation, and appropriate hardware, the effects of a large portion of attacks can be reduced