The Open IMS Core is an implementation of IMS Call Session Control Functions (CSCFs) and a lightweight Home Subscriber Server (HSS), which together form the core elements of all IMS/NGN architectures as specified today within 3GPP, 3GPP2, ETSI TISPAN and the PacketCable intiative. The four components are all based upon Open Source software(e.g. the SIP Express Router (SER) or MySQL).
Download OpenIMSCore r551 VMware image (~200 mb)
Username/password: root/password
This image is based on Gentoo linux. To use this image you must download free VMware player