A central issue in the design of modern communication networks is that of providing performance guarantees. This issue is particularly important if the networks support real-time traffic such as voice and video. The most critical performance parameter to bound is the delay experienced by a packet as it travels from its source to its destination. We study dynamic routing in a connection-oriented packet-switching network. We consider a network with arbitrary topology on which a set of sessions is defined. For each session i, packets are injected at a rate ri to follow a predetermined path of length di. Due to limited bandwidth, only one packet at a time may advance on an edge (link). Session paths may overlap subject to the constraint that the total rate of sessions using any particular edge is at most 1 − ε for any constant ε ∈ (0, 1). We address the problem of scheduling the sessions at each switch, so as to minimize worst-case packet delay and queue buildup at the switches. We ...