Iperf is a modern alternative for measuring TCP and UDP bandwidth performance, allowing the tuning of various parameters and characteristics.

Features: * Measure bandwidth, packet loss, delay jitter * Report MSS/MTU size and observed read sizes. * Support for TCP window size via socket buffers. * Multi-threaded. Client and server can have multiple simultaneous connections. * Client can create UDP streams of specified bandwidth. * Multicast and IPv6 capable. * Options can be specified with K (kilo-) and M (mega-) suffices. * Can run for specified time, rather than a set amount of data to transfer. * Picks the best units for the size of data being reported. * Server handles multiple connections. * Print periodic, intermediate bandwidth, jitter, and loss reports at specified intervals. * Server can be run as a daemon. * Use representative streams to test out how link layer compression affects your achievable bandwidth.