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