Cell delay variation is one of the major disadvantages of the ATM technique. In broadband ISDN, cell propagation delay along a virtual connection fluctuates because of the variable delays introduced in the network by the queues at switches and multiplexers. The authors consider the case of a constant bit rate source (CBR) accessing B-ISDN from a DQDB metropolitan area network. They first underline the necessity of a peak cell rate enforcement entity at the UNI between the DQDB network and the ATM access. They then investigate the suitability of a new traffic shaper so-called spacer-controller to police peak cell rate at the output of a DQDB/B-ISDN gateway. The case of a DQDB-ATM multi-connection environment is also considered.>