Seagull is a multi-protocol traffic generator. Especially targeted towards IMS, Seagull supports Diameter (RFC3588 and all applications) over TCP/SCTP and IPv4/IPv6 , TCAP (over SS7 or Sigtran), XCAP over HTTP and Radius.
CDNsim is a GNU/LINUX simulation tool for CDNs, written in C++ (core) and python (GUI wizard). It models: redirection policies, cache policies, TCP/IP, batch simulations, statistics extraction and more. CDNsim is uses the OMNet++ library