The use of Application Level Multicast (ALM) is extremely promising for content distribution.F or these applications appropriate cost functions for deciding between different ALM tree configurations are required, and for these cost functions bandwidth measurement mechanisms are most likely to be important.Existing end-to-end measurement techniques cannot address several ALM and network topology scenarios. Enhancing existing techniques with cooperation mechanisms allows them to cope with the specificity of ALM, namely with transport link sharing.Sim ulation results indicate that these techniques can produce estimates with reasonable accuracy.