RRDTool (light intensity)

Subject: Best Practices in Communication Networks II (PKS II), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Date of presentation: October 25, 2024 introduction In the field of monitoring, the vizualisation tools are vital for the human operators to analyze the currect situation on the network, hardware or in the system, and to decide on the operation being executed next. implementation used hardware and software Raspberry Pi 4B 8GB + GPIO simple breadboard and wires VISHAY BPV10NF photodiode rrdtool wiring up Fig....

October 23, 2024 · 3 min · 555 words · krusty

Modern monitoring tools and methods to guarantee high availability

Subject: Cyber Security II (KB II), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO Name: Bc. Kryštof Šara (SAR0130) Date of presentation: May 10, 2024 Task syllabus: design and configuration of test topology using network monitoring tools - Zabbix, Nagios, including their configuration description of the methods used to maintain high availability and their practical example introduction As far as modern computational systems are concerned, it is common to ensure those are operational no matter what happens....

May 9, 2024 · 18 min · 3720 words · krusty

Dial-up over VoIP service ISP

Annotation: Telecommunications laboratory (telco lab) is the next step in the old hardware collection’s further usage and analysis. About 10+ various [mainly U.S.Robotics (USR) branded] voice 56kbit (fax)modems for dial-up Internet connection had been collected. This article gives a Prove of Concept (PoC) to the modem-modem link establishment over the VoIP RTP stream with aim to build a dial-in ISP service. Various VoIP technology’s underlying parameters, and modem configurations had been tuned with batch dial-up connection testing being executed, and then commented....

January 14, 2024 · (last updated October 1, 2024) · 51 min · 10849 words · krusty

Advanced VPN configuration using WireGuard

Subject: Cyber Security I (KB I), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Date of presentation: December 15, 2023 Task description: Application description, testbed creation, implementation of some of the most well-known scenarios for VPN - 1: 1 and N: 1, connection of PKI with VPN introduction In the modern era of digital nomadism, where one can roam virtually anywhere around the globe, while still having a connection to public Internet, it is crutial to ensure an additional layer of security for businesses as well as for individuals (public WiFi access points)....

December 8, 2023 · 17 min · 3437 words · krusty

Plain HTTP safety in WireGuarded networks

Subject: Cyber Security I (KB I), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Date of presentation: December 15, 2023 introduction In the modern era, it is a standard to ensure HTTP over SSL/TLS layer (HTTPS) on any web page possible. However, the implementation of Public Key Infrastructure (PKI), such as getting the keys and certificates can be a problem, when using internal domain name systems and internal domains, that are not accessible from the Internet....

December 8, 2023 · 6 min · 1148 words · krusty

Methods and technologies for SRTP media stream decryption

Subject: Multimedia Communication and Content Security (MZKO), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Task syllabus: master key exchange (symetric cryptography) SRTP-DES exchange, SIP VoIP, SDP session descriptor, RTP stream description (codecs, media type, ports, SRTP master key in bae64) in SIP signalling key distribution problem (MitM-prone) ZRTP and Diffie-Hellmann (DH) alg (MitM-prone and DH implementation in old HW problem) SRTP-DTLS session, WebRTC over DTLS channel, media encryption simulation introduction In the world of a continuous need for communication (preferably in real-time), it is vital for the media stream transportation to be reliable (uninterrupeted), secure (end-to-end encrypted, and fast (UDP/IP, low jitter and RTT)....

15 min · 3107 words · krusty