VoIP session has specific transport requirements and associated mechanism for voice synchronization such as RTP/UDP or TCP. To maintain the quality of service during the conversation, Resource Reservation Protocol (RSVP) and Differentiated service DIFF-SERV protocols are used. Advantages, limitations and work-around solutions for the transport protocols used in VoIP session are described. Selection criteria such as ease of implementation, performance, security and interoperability are discussed for implementation in residential gateways.