The growing complexity of customizable embedded multiprocessor architectures for digital media processing will soon require highly scalable network-on-chip based communication infrastructures. Here, we propose xpipes, a scalable and high-performance NoC architecture for multiprocessor SoCs, consisting of soft macros that can be turned into instance-specific network components at instantiation time. The flexibility of its components allows our NoC to support both homogeneous and heterogeneous architectures. The interface with IP cores at the periphery of the network is standardized (OCP-based). Links can be pipelined with a flexible number of stages to decouple data introduction speed from worst-case link delay. Switches are lightweight and support reliable communication for arbitrary link pipeline depths (latency insensitive operation). Xpipes has been described in synthesizable SystemC, at the cycle-accurate and signal-accurate level.