|
|
Detection of VoIP Applications in Network Statistics
Havelka, Ondřej ; Tobola, Jiří (referee) ; Žádník, Martin (advisor)
VoIP applications allow us fast and cheap communication over the internet. Due to the massive expansion of these applications in last few years, there is growth of VoIP traffic, which is needed to distinguish from other traffic. Detection of VoIP applications is related to data monitoring and network traffic classification. The work focuses on detection of these applications: GTalk, ICQ, Skype, WLM a Yahoo. There are presented two detection techniques. First of them is based on behavior of VoIP applications. This technique uses the statistical characteristics of network flows as packet frequency and packet size. The second method is based on searching for patterns in packet contents. These packets carry voice data using protocol RTP. Both techniques were experimentally verified and the results are presented in the work.
|
|
|
Communication systems based on IP telephony
Zimek, Josef ; Kapoun, Vladimír (referee) ; Herman, Ivo (advisor)
My master’s thesis is focused on designing and creating communication network, which provides communication between two independent networks through encrypted tunnel. My solution is based on routers formed by older personal computers with FreeBSD like a operating system. Between routers is created static encrypted tunnel by using IPSec protocol. Voice services provides packet oriented exchange Asterisk with support of signaling protocol SIP. This solution can be used eg. for connecting remote branch to headquarters of company and then can branch utilize shrared resources. To headquarters can connect also remote workers from their home. In this case are used SSL certificates to authentication of user. This scenario is very required today.
|
|
|
VoIP Quality Analyzer
Havelka, Ondřej ; Žádník, Martin (referee) ; Tobola, Jiří (advisor)
This master thesis deals with the design and implementation of an application for analyzing Voice over IP quality using NetFlow. In the beginning, there is summarized basic information about VoIP technology and NetFlow - its principles, the most used protocols, factors that have influence on call quality and call quality rating methods. Later there is presented proposal of application and then described its implementation. The created application was tested on samples, which simulate calls in network with delays and packet-loss. Within testing was made the comparison with commercial application and the results are discussed.
|
|
|
Network Protection Using NetFlow Data
Sedlář, Petr ; Žádník, Martin (referee) ; Tobola, Jiří (advisor)
This document provides information about Cisco NetFlow technology and its usage to protect networks from different types of attacks. Part of the document is a summary of common security risks in term of their detection on network and transport layer. There are specified characteristics of NetFlow data containing samples of security risks. On the basis of these characteristics, an application for detection these risks is designed and implemented.
|
|
|
Home VoIP
Bílek, Tomáš ; Ščuglík, František (referee) ; Ráb, Jaroslav (advisor)
The thesis explores practical applications of VoIP technology at home, in combination with the opensource private branch exchange Asterisk. A substantial part of this work is the documentation of the functioning of the main parts of public switched telephone networks (PSTN) and VoIP networks. Also described are the principles of voice digitization, commonly used codecs and several VoIP protocols. The last part of the thesis focuses on the design, practical realization and verification of two home VoIP installations.
|
|
| |
|
| |
|
|
Home VoIP
Bílek, Tomáš ; Ščuglík, František (referee) ; Ráb, Jaroslav (advisor)
The thesis explores practical applications of VoIP technology at home, in combination with the opensource private branch exchange Asterisk. A substantial part of this work is the documentation of the functioning of the main parts of public switched telephone networks (PSTN) and VoIP networks. Also described are the principles of voice digitization, commonly used codecs and several VoIP protocols. The last part of the thesis focuses on the design, practical realization and verification of two home VoIP installations.
|
|
|
Detection of VoIP Applications in Network Statistics
Havelka, Ondřej ; Tobola, Jiří (referee) ; Žádník, Martin (advisor)
VoIP applications allow us fast and cheap communication over the internet. Due to the massive expansion of these applications in last few years, there is growth of VoIP traffic, which is needed to distinguish from other traffic. Detection of VoIP applications is related to data monitoring and network traffic classification. The work focuses on detection of these applications: GTalk, ICQ, Skype, WLM a Yahoo. There are presented two detection techniques. First of them is based on behavior of VoIP applications. This technique uses the statistical characteristics of network flows as packet frequency and packet size. The second method is based on searching for patterns in packet contents. These packets carry voice data using protocol RTP. Both techniques were experimentally verified and the results are presented in the work.
|
|
|
Network Protection Using NetFlow Data
Sedlář, Petr ; Žádník, Martin (referee) ; Tobola, Jiří (advisor)
This document provides information about Cisco NetFlow technology and its usage to protect networks from different types of attacks. Part of the document is a summary of common security risks in term of their detection on network and transport layer. There are specified characteristics of NetFlow data containing samples of security risks. On the basis of these characteristics, an application for detection these risks is designed and implemented.
|
guest ::
