Transport Layer Protocols Taxonomy from Voice over Ip Perspective

VoIP technology is becoming increasingly important as they gain market share in PSTN technology. In the short run, it is likely that VoIP technology will dominate the telecommunications market. This evolution towards VoIP technology makes sense for improving the VoIP technology efficiency under the auspices of the internet. However, the PSTN still provide voice quality better than the VoIP technology voice quality. This would be due to many contributing factors such as delay and packet loss. Apart from internet hardware infrastructure, the VoIP transfer protocols cause the delay and packet loss problems as well. Typically, the Real-time Media Transfer Protocols (RTMTPs), such as the Real-time Transport Protocol (RTP), are working in conjunction with the transport layer protocols (TLPs) to carry the VoIP applications data. However, some of the TLPs protocols are transfer the VoIP applications data by themselves. The aim of this paper is to present the capability of the TLPs protocols to transfer the VoIP applications data, and the obstacles face these protocols to do so. For easier comparison and discussion, we have divided TLPs protocols into three groups, the Reliable Transport Layer Protocols (RTLPs), Unreliable Transport Layer Protocols (UTLPs), and Reliable and Unreliable Transport Layer Protocols (RUTLPs). We have studied the three groups from VoIP point of view. In addition, we have showed that the UTLPs group needs to work with the RTMTPs to be able to transfer the VoIP applications data. Finally, we have showed the problems caused by each group to the VoIP applications. As result, a comparison among the transport layer protocols is presented according to the problems resulting from theses protocols when transferring the VoIP applications data. The comparison can help to choose the suitable protocols to carry the VoIP data. However, after studied all the TLPs protocols, the paper recommend to use the UTLPs group in conjunction with the RTMTPs, in order to transfer the VoIP applications data.