This memorandum is a companion document to the current version of the RTP protocol speci cation draft-ietf-avt-rtp-*.ftxt,psg. It discusses protocol aspects of transporting real-time services (for example, voice or video) over packet-switched networks such as the Internet. It compares and evaluates design alternatives for a real-time transport protocol, providing rationales for the design decis...

The Session Initiation Protocol (SIP) has become the most predominant protocol for Voice over Internet Protocol (VoIP) signaling. Security of SIP is an important consideration for VoIP communication as the traffic is transmitted over the insecure IP network. And the authentication process in SIP ranges from preshared secret based solutions to Public Key Infrastructure (PKI) based solution. Howe...

In recent years Voice over Internet Protocol (VoIP) has become a popular multimedia application over the Internet. At the same time critical security issues in VoIP have started to emerge. The Session Initiation Protocol (SIP) is a predominant signalling protocol for VoIP. It is used to establish, maintain and terminate VoIP calls, playing a crucial role in VoIP. This paper is aimed at developi...

30 years ago PABX systems were compromised by hackers wanting to make long distance calls at some other entities expense. This activity faded as telephony became cheaper and PABX systems had countermeasures installed to overcome attacks. Now the world has moved onto the provision of telephony via broadband enabled Voice over Internet Protocol (VoIP) with this service now being provided as a rep...

Over 48 million end users worldwide utilize cable modems as their means of accessing the Internet at high speeds. Networks which provide access via cable modems utilize Data Over Cable Service Interface Specifications (DOCSIS) as their means of network management. As availability and utilization to the Internet increases (especially at high speeds supported by broadband access), so does the opp...

For transporting voice data with silence suppression over the Internet, the problem of jitter introduced from the network often renders the speech unintelligible. It is thus essential to offer intramedia synchronization to remove jitter while retaining minimal playout delay. We have previously proposed a neural– network–based intra–voice synchronization mechanism, called Intelligent Voice Smoot...

Actually, wealthy network services such as Internet protocol television (IPTV) and Voice over IP (VoIP) are expected to become more pervasive over the Next Generation Network (NGN). In order to serve this purpose, the quality of these services should be evaluated subjectively by users. This is referred to as the quality of experience (QoE). However, there are many issues that may impact user’s ...

The VoIP(Voice over IP) has been worldwide used and already put to practical use in many fields. However, it is needed to ensure secret of VoIP call in a special situation. It is relatively difficult to eaves-drop the commonly used PSTN in that it is connected with 1:1 circuit. However, it is difficult to ensure the secret of call on Internet because many users can connect to the Internet at th...