Providing rate guarantees for Internet application traffic across ATM networks

The TCP/IP protocol suite is the standard requirement for all applications that need to communicate over the Internet. As TCP/IP applications are unab le to specify the QoS parameters needed for most Asynchronous Transfer Mode (ATM) services, they tend to use the unspecified bit rate (UBR) service ca tegory when running across ATM networks. The UBR service utilizes any bandw idth that is left unused by the rest of the ATM services. This has led the ATM Forum's Traffic Management Group to define a new service category calle d guaranteed frame rate (GFR). GFR is intended to provide minimum cell rate guarantees and fair access to excess bandwidth left over from higher-prior ity services. This article first presents a tutorial overview of GFR and th en presents a survey of the research work that has been carried out toward the design and implementation of associated ATM switch mechanisms.