Evaluation of SIP Signalling and QoS for VoIP over OLSR MANET Routing Protocol

Abstract: This paper evaluates the SIP based VoIP applications over the Optimized Link State Routing protocol (OLSR) as a proactive routing protocol for Mobile Ad Hoc Networks (MANET) using Static, Uniform, and Random mobility models. The evaluation considered PCM, LQS, IPTelephony, and GSM voice codecs to study the SIP signaling performance and the voice Quality of Service (QoS) for VoIP calls over OLSR MANET. The simulation efforts performed in OPNET Modeler 17.1. The results show that VoIP over OLSR MANET has good performance over Static and Uniform mobility models while it has variable performance with Random models. SIP signaling has large delays compared with the voice signaling which reduce the VoIP performance and increases the call's duration. In addition, GSM and LQS based VoIP calls have an acceptable level of QoS while PCM and IP-Telephony based VoIP calls have a low level of QoS over different types of mobility models. Furthermore, the location and the mobility of SIP server affect the number of hops and the SIP signaling performance between the different parties of the VoIP call

Cryptanalysis and improvement of password-authenticated key agreement for session initiation protocol using smart cards

Session Initiation Protocol (SIP) is one of the most commonly used protocols for handling sessions for Voice over Internet Protocol (VoIP)-based communications, and the security of SIP is becoming increasingly important. Recently, Zhang et al. proposed a password authenticated key agreement protocol for SIP by using smart cards to protect the VoIP communications between users. Their protocol provided some unique features, such as mutual authentication, no password table needed, and password updating freely. In this study, we performed cryptanalysis of Zhang et al.'s protocol and found that their protocol was vulnerable to the impersonation attack although the protocol could withstand several other attacks. A malicious attacker could compute other users’ privacy keys and then impersonated the users to cheat the SIP server. Furthermore, we proposed an improved password authentication key agreement protocol for SIP, which overcame the weakness of Zhang et al.’s protocol and was more suitable for VoIP communications

A new security architecture for SIP based P2P computer networks

Many applications are transferred from C/S (Client/Server) mode to P2P (Peer-to-Peer) mode such as VoIP (Voice over IP). This paper presents a new security architecture, i.e. a trustworthy authentication algorithm of peers, for Session Initialize Protocol (SIP) based P2P computer networks. A mechanism for node authentication using a cryptographic primitive called one-way accumulator is proposed to secure the P2P SIP computer networks. It leverages the distributed nature of P2P to allow for distributed resource discovery and rendezvous in a SIP network, thus eliminating (or at least reducing) the need for centralized servers. The distributed node authentication algorithm is established for the P2P SIP computer networks. The corresponding protocol has been implemented in our P2P SIP experiment platform successfully. The performance study has verified the proposed distributed node authentication algorithm for SIP based P2P computer networks

An energy efficient authenticated key agreement protocol for SIP-based green VoIP networks

Voice over Internet Protocol (VoIP) is spreading across the market rapidly due to its characteristics such as low cost, flexibility implementation, and versatility of new applications etc. However, the voice packets transmitted over the Internet are not protected in most VoIP environments, and then the user’s information could be easily compromised by various malicious attacks. So an energy-efficient authenticated key agreement protocol for Session Initial Protocol (SIP) should be provided to ensure the confidentiality and integrity of data communications over VoIP networks. To simplify the authentication process, several protocols adopt a verification table to achieve mutual authentication, but the protocols require the SIP server to maintain a large verification table which not only increases energy consumption but also leads to some security issues. Although several attempts have been made to address the intractable problems, designing an energy-efficient authenticated key agreement protocol for SIP-based green VoIP networks is still a challenging task. In this study, we propose an efficient authentication protocol for SIP by using smartcards based on elliptic curve cryptography. With the proposed protocol, the SIP server needs not to store a password or verification table in its database, and so no energy is required for the maintenance of the verification table. Security analysis demonstrates that the proposed protocol can resist various attacks and provides efficient password updating. Furthermore, the experimental results show that the proposed protocol increases efficiency in comparison with other related protocols

MEMBANGUN SERVER VOIP BERBASIS ASTERISK DENGAN SISTEM OPERASI UBUNTU 9.04

Wiwin Lusiana, 2009. Building Asterisk-Based VOIP Server using 9.04 Ubuntu Operating System. Computer Science Diploma III Program of Mathematics and Sciences Faculty of Surakarta Sebelas Maret University. Voice over Internet Protocol (VoIP) is a technology utilizing the Internet Protocol to provide the voice communication electronically and in real-time manner. VoIP technology is the recent telecommunication technology, in which the cost spent for this technology’s infrastructure is much cheaper than other telecommunication technology commonly used by the public currently. The elements composing VoIP include: User agent, proxy, protocol and Coder- Decoder (CODEC). Asterisk is a softswitch to operate the proxy based on the session initiation protocol (SIP). The 9.04 Ubuntu operating system as the VoIP served is flexible enough to support the asterisk package performance. The objective of research is to build Asterisk based-VoIP server, in order to be developed in the future research according to the requirement. The research method employed mainly consisted of two ways: literary study and experiment. This research was done in the institution with the intranet network built previously. Thus, VoIP here function as the maximizer of existing intranet network to reduce the expenditure for communication requirement. The service provided in this study include voice and video with the call client to server, call client to client, video call, conference, video conference and mailbox/voicemail services. Keywords: Voice over Internet Protocol (VoIP), Asterisk, Session Initiation Protocol (SIP), 9.04 Ubuntu

A new security architecture for SIP-based P2P computer networks

Many applications are transferred from C/S (Client/Server) mode to P2P (Peer-to-Peer) mode such as VoIP (Voice over IP). This paper presents a new security architecture, i.e. a trustworthy authentication algorithm of peers, for Session Initialize Protocol (SIP) based P2P computer networks. A mechanism for node authentication using a cryptographic primitive called one-way accumulator is proposed to secure the P2P SIP computer networks. It leverages the distributed nature of P2P to allow for distributed resource discovery and rendezvous in a SIP network, thus eliminating (or at least reducing) the need for centralized servers. The distributed node authentication algorithm is established for the P2P SIP computer networks. The corresponding protocol has been implemented in our P2P SIP experiment platform successfully. The performance study has verified the proposed distributed node authentication algorithm for SIP based P2P computer networks

Intrusion detection mechanisms for VoIP applications

VoIP applications are emerging today as an important component in business and communication industry. In this paper, we address the intrusion detection and prevention in VoIP networks and describe how a conceptual solution based on the Bayes inference approach can be used to reinforce the existent security mechanisms. Our approach is based on network monitoring and analyzing of the VoIP-specific traffic. We give a detailed example on attack detection using the SIP signaling protocol