Session Initiation Protocol (SIP) is a signaling protocol emerged with an aim to enhance the IP network capabilities in terms of complex service provision. SIP server scalability with load balancing has a greater concern due to the dramatic increase in SIP service demand. Load balancing of session method (request/response) and security measures optimizes the SIP server to regulate of network tr...

Voice over IP (or VoIP) has been adopted progressively not only by a great number of companies but also by an expressive number of people, in Brazil and in other countries. However, this crescent adoption of VoIP in the world brings some concerns such as security risks and threats, mainly on the privacy and integrity of the communication. The risks and threats already exist in the signaling pro...

The purpose of this paper is to provide a framework for detecting vulnerabilities in SIP (Session Initiation Protocol) networks. We focused our studies on the detection of SIP DoS related vulnerabilities in VoIP infrastructures because of their generalization. We try to find weaknesses in SIP enabled entities that an attacker by exploiting them is able to attack the system and affect it. This f...

In our modern society telephony has developed to an omnipresent service. People are available at anytime and anywhere. Furthermore the Internet has emerged to an important communication medium. These facts and the raising availability of broadband internet access has led to the fusion of these two services. Voice over IP or short VoIP is the keyword, that describes this combination. The advanta...

The current penetration, but also the huge potential, of Voice over IP (VoIP) telephony services in the market, boosts the competition among telecommunication service providers who promote new services through many different types of offers. However, this transition from the closed Public Switched Telephone Network (PSTN) architecture to the internet based VoIP services, has resulted in the int...

VoIP service is the transmission of voice data using SIP protocol on an IP-based network. The SIP protocol has many advantages, such as providing IP-based voice communication and multimedia service with low communication cost. Therefore, the SIP protocol disseminated quickly. However, SIP protocol exposes new forms of vulnerabilities to malicious attacks, such as message flooding attack. It als...

In the 3rd generation multimedia communication world and in the 3GPP standardization consortium, SIP protocol appears to be the preferred signaling protocol. However, the need to communicate with non-SIP based network, e.g. H.323 from ITU-U, is still a reality. The need can be satisfied with the introduction of network gateways (also named Inter-Working Function). One of the open issues about S...

Briefly speaking, there are two popular Voice over Internet Protocol (VoIP) standards, H.323 and Session Initiation Protocol (SIP). The first standard was designed by ITU and has become the basis for the widespread implementation of VoIP systems although it was not specifically designed for it. The second standard, SIP, was proposed by IETF and it is designed to connect, communicate and exchang...

This document defines a Session Initiation Protocol (SIP) event package that enables the collection and reporting of metrics that measure the quality for Voice over Internet Protocol (VoIP) sessions. Voice call quality information derived from RTP Control Protocol Extended Reports (RTCP-XR) and call information from SIP is conveyed from a User Agent (UA) in a session, known as a reporter, to a ...

SIP (Session Initiation Protocol) is becoming the mostly deployed signaling protocol for VoIP (Voice over IP). Security is of utmost importance for its usage due to the open architecture of the Internet. Recently, Yoon et al. proposed a SIP authentication scheme based on elliptic curve cryptography (ECC) that claimed to provide higher security than other schemes. However, as demonstrated in thi...