The volume of network traffic, notably of data traffic, grows continuously and tremendously during recent years with the appearance of new value-added services such as video on demand, interactive video conferencing, peer to peer data sharing, etc. Faced with this challenge, traditional circuit-switched networks become inappropriate and costly. On the other side, optical packet-switched networks, which support best data traffic thanks to their high flexibility, capacity, and cost-efficiency, appear the most appropriate candidate. To optimise the transmission efficiency of packets in optical networks, a new technology, Modified Packet Bursting (MPB), has been studied in the framework of a metropolitan optical packet bus-based network. Also, in order not to degrade the quality of classical circuit-switched Time Division Multiplexing (TDM) services, which still stay the major revenues of telecom operators today, Circuit Emulation Service (CES) on packet-switched networks has been investigated by main standard organizations. This paper presents the performance analysis of the above two technologies applied to a metropolitan optical packet bus-based network. It specially demonstrates the improvement of CES performance thanks to MPB featur