Security in Peer-to-Peer SIP VoIP

VoIP (Voice over Internet Protocol) is one of the fastest growing technologies in the world. It is used by people all over the world for communication. But with the growing popularity of internet, security is one of the biggest concerns. It is important that the intruders are not able to sniff the packets that are transmitted over the internet through VoIP. Session Initiation Protocol (SIP) is the most popular and commonly used protocol of VoIP. Now days, companies like Skype are using Peer-to-Peer SIP VoIP for faster and better performance. Through this project I am improving an already existing Peer-to-Peer SIP VoIP called SOSIMPLE P2P VoIP by adding confidentiality in the protocol with the help of public key cryptography

Signaling for Internet Telephony

Internet telephony must offer the standard telephony services.However, the transition to Internet-based telephony services also provides an opportunity to create new services more rapidly and with lower complexity than in the existing public switched telephone network(PSTN). The Session Initiation Protocol (SIP) is a signaling protocol that creates, modifies and terminates associations between Internet end systems, including conferences and point-to-point calls. SIP supports unicast, mesh and multicast conferences, as well as combinations of these modes. SIP implements services such as call forwarding and transfer, placing calls on hold, camp-on and call queueing by a small set of call handling primitives. SIP implementations can re-use parts of other Internet service protocols such as HTTP and the Real-Time Stream Protocol (RTSP). In this paper, we describe SIP, and show how its basic primitives can be used to construct a wide range of telephony services

Implementación y pruebas de REsource LOcation And Discovery (RELOAD) Parser and Encoder

El ampliamente utilizado paradigma cliente/servidor está siendo complementado e incluso reemplazado por otros planteamientos de tipo Peer-to-Peer (P2P). Las redes P2P ofrecen un sistema descentralizado de distribución de la información, son más estables, y representan una solución al problema de la escalabilidad. Al mismo tiempo, el Session Initiation Protocol (SIP), un protocolo de señalización diseñado inicialmente para arquitecturas de tipo ciente/servidor, ha sido ampliamente adoptado para servicios de comunicación tipo Voice-over-IP (VoIP). El actual proceso de estandarización llevado a cabo por el Peer-to-Peer Session Initiation Protocol (P2PSIP) Working Group del IETF se está acercando al desarrollo de aplicaciones que puedan utilizar tecnologías P2P junto con SIP. RELOAD es un protocolo P2P de señalización, que está todavía en desarrollo. RELOAD trabaja en entornos en los que existen Network Address Translators (NATs) o firewalls. RELOAD soporta diferentes aplicaciones y proporciona un marco de seguridad, también permite el uso de diversos algoritmos para las Distributed Hash Tables (DHTs) mediante los llamados "topology plugins". Esta tesis tiene como objetivos la implementación de un codificador y decodificador para mensajes de RELOAD, y el análisis de su rendimiento. Para este último punto se implementará un programa de prueba ejecutable en un teléfono móvil y en un servidor para la simulación de una red RELOAD. ________________________________________The widely used classic client/server paradigm is being complemented and sometimes replaced by current Peer-to-Peer (P2P) approaches. P2P networks offer decentralized distribution of information, are more stable, and represent a solution to the problem of scalability. At the same time the Session Initiation Protocol (SIP), a signalling protocol initially designed for client/server architectures, has been widely adopted for Voice-over-IP (VoIP) communication. The current standardization process of the Peer-to-Peer Session Initiation Protocol (P2PSIP) working group of the IETF is moving towards the development of applications that can use both P2P and Session Initiation Protocol (SIP) technologies in conjuntion. RELOAD is a P2P signalling protocol, which is still under development. RELOAD works in environments where there are Network Address Translators (NATs) or firewalls. RELOAD can support various applications and provides a security frameworks. RELOAD also allows the use of various Distributed Hash Table (DHT) algorithms in the form of topology plugins. This thesis aims at implementing a parser and encoder for RELOAD messages, and analyzing its performance by implementing a test program that will run on a mobile phone and on a server simulating a RELOAD overlay network.Ingeniería Técnica en Informática de Gestió

Using an External DHT as a SIP Location Service

Peer-to-peer Internet telephony using the Session Initiation Protocol (P2P-SIP) can exhibit two different architectures: an existing P2P network can be used as a replacement for lookup and updates, or a P2P algorithm can be implemented using SIP messages. In this paper, we explore the first architecture using the OpenDHT service as an externally managed P2P network. We provide design details such as encryption and signing using pseudo-code and examples to provide P2P-SIP for various deployment components such as P2P client, proxy and adaptor, based on our implementation. The design can be used with other distributed hash tables (DHTs) also

Efficient User Controlled Inter-Domain SIP Mobility: Authentication, Registration, and Call Routing

Over the past decade, multimedia services have gained significant acceptance and played an important role in the convergence of IP networks. Supporting mobility in IP (Internet Protocol) networks is a crucial step towards satisfying the nomadic communication paradigms on the current Internet. The Session Initiation Protocol (SIP) presents one approach towards supporting IP mobility. Additionally, SIP is increasingly gaining in popularity as the next generation multimedia signaling and session establishment protocol. It is anticipated that the SIP infrastructure will be extensively deployed all over the Internet. In this paper, we explore an efficient approach to inter-domain SIP mobility in an attempt to improve personal and terminal mobility schemes. We succeed in applying a persistent identification framework to application level SIP addressing by introducing a level of indirection on top of the traditional SIP architecture. We refer to our approach as the Handle SIP (H-SIP). H-SIP leverages the current SIP architecture abstracting any domain binding from users. Our approach to mobility is user-controlled. We experimentally prove the efficiency of H-SIP in achieving inter-domain authentication and call routing through modeling and real-time measurements

Prototyping a peer-to-peer session initiation protocol user agent

The Session Initiation Protocol (SIP) has in recent years become a popular protocol for the exchange of text, voice and video over IP networks. This thesis proposes the use of a class of structured peer to peer protocols - commonly known as Distributed Hash Tables (DHTs) - to provide a SIP overlay with services such as end-point location management and message relay, in the absence of traditional, centralised resources such as SIP proxies and registrars. A peer-to-peer layer named OverCord, which allows the interaction with any specific DHT protocol via the use of appropriate plug-ins, was designed, implemented and tested. This layer was then incorporated into a SIP user agent distributed by NIST (National Institute of Standards and Technology, USA). The modified user agent is capable of reliably establishing text, audio and video communication with similarly modified agents (peers) as well as conventional, centralized SIP overlays

Sequential Protocols’ Behaviour Analysis

The growing adoption of the Session Initiation Protocol (SIP) has motivated the development of tools capable of detecting valid SIP dialogues, in order to potentially identify behavioural traits of the protocol. This thesis serves as a starting point for characterising SIP dialogues, in terms of distinct signalling sequences, and providing a reliable classification of SIP sequences. We start by analysing sequential pattern mining algorithms in an off-line manner, providing valuable statistical information regarding the SIP sequences. In this analysis some classical Sequential Pattern Mining algorithms are evaluated, to gather insights on resource consumption and computation time. The results of the analysis lead to the identification of every possible combinations of a given SIP sequence in a fast manner. In the second stage of this work we study different stochastic tools to classify the SIP dialogues according to the observed SIP messages. Deviations to previously observed SIP dialogues are also identified. Some experimental results are presented, which adopt the Hidden Markov Model jointly used with the Viterbi algorithm to classify multiple SIP messages that are observed sequentially. The experimental tests include a stochastic dynamic evaluation, and the assessment of the stochastic similarity. The goal of these tests is to show the reliability and robustness of the algorithms adopted to classify the incoming SIP sequences, and thus characterizing the SIP dialogues