%0 Journal Article %A Heru Nurwarsito and R. Arief Setyawan and Rakhmadhany Primananda %D 2010 %J International Journal of Electronics and Communication Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 43, 2010 %T Implementation of the SIP Express Router with Mediaproxy Method on VoIP %U https://publications.waset.org/pdf/15614 %V 43 %X Voice Over IP (VoIP) is a technology that could pass the voice traffic and data packet form over an IP network. Network can be used for intranet or Internet. Phone calls using VoIP has advantages in terms of cheaper cost of PSTN phone to more than half, because the cost is calculated by the cost of the global nature of the Internet. Session Initiation Protocol (SIP) is a signaling protocol at the application layer which serves to establish, modify, and terminate a multimedia session involving one or more users. This SIP signaling has SIP message in text form that is used for session management by the SIP components, such as User Agent, Registrar, Redirect Server, and Proxy Server. To build a SIP communication is required SIP Express Router (SER) to be able to receive SIP messages, for handling the basic functions of SIP messages. Problems occur when the NAT through which affects the voice communication will be blocked starting from the sound that is not sent or one side of the sound are sent (half duplex). How that could be used to penetrate NAT is to use a given mediaproxy random RTP port to penetrate NAT. %P 1044 - 1049