This standard is a supplement to ISO/IEC 8802-6: 1994. Applications requiring bandwidth guarantees and delay limits are common and the need has been identified to support such applications on a DQDB subnetwork. Those requirements can be achieved by using either the Pre-Arbitrated (PA) functions (see IEEE Std 802.6h-19931) or the Queued Arbitrated (QA) functions. This standard focuses on the use of enhanced QA functions. The Guaranteed Bandwidth (GBW) protocol is specified as an enhancement of the QA Functions block. Moreover, Connection-Oriented Convergence Functions (COCFs) using the enhanced QA functions are necessary to support connection-oriented service. Different COCFs optimized for different types of applications are envisaged on top of the QA Functions block, using for example, AAL3/4 or AAL5. However, in this standard, only the COCF block using AAL3/4 is fully specified. This standard does not specify procedures for establishing, maintaining, and releasing connections.