Two-way SIP-based voice gateway with bandwidth management: Transportal

• Main Authors: Lim, Christopher John S., Ng, Jon Gratton D., Santillan, John Edward C., Tomeldan, Christian Bernard S.
• Format: text
• Language: English
• Published: Animo Repository 2010
• Subjects: Computer network protocols; Internet telephony; Digital telephone systems; Multimedia systems; Database management
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/14651
• Institution: De La Salle University

Session Initiation Protocol (SIP) is a versatile technology that allows various types of multimedia connection session [1] such as Internet telephony through softphones. A softphone is a software program used on the Internet which mimics services similar to that of regular telephones. An example of a softphone that implements SIP is VoIPBuster [2]. Aside from softphone to softphone conversation, VoIPBuster has the ability to connect softphones to regular telephone line for a limited time. However, the service has a rate of subscription. As an alternative to the service for subscription offered by VoIPBuster, voice gateway devices were developed. Voice gateways were made to act as portals between the Internet and the Public Switched Telephone Network (PSTN). Grandstream, an example of an existing voice gateway, has proven that a connection between an Internet’s softphone and regular telephone is possible for Small Office Home Office (SOHO) users [4]. It is interoperable with softphones which implements SIP standards. This means that softphones like VoIPBuster can be used with voice gateways like Grandstream. However, Grandstream does not give assurance that it can provide a toll quality voice conversation between a softphone and a regular phone. As a result, voice transmitted becomes choppy to the receiver. On the other hand, there are voice gateways designed for corporate level that offers a better service. An example of this corporate level voice gateway is Verso [5] [6]. As opposed to Grandstream, Verso supports bandwidth management [3] which leads to a toll quality voice communication between a softphone and a regular phone. Nevertheless, it is impractical for SOHO users to purchase voice gateways like Verso not only because it is too expensive but also because it offers too many services which are not necessary for a typical SOHO environment. In addition, it implements a proprietary protocol which is different from SIP standards. This study presents an implementation of SIP-based voice gateway with bandwidth management intended for SOHO users. Based on the experiments, 7 out of 10 respondents have shown that a softphone can achieve a toll quality conversation when connected to a regular phone and vice versa.