Peers is a very minimalistic SIP User-Agent. It s a softphone, written in java, and it has been tested on linux and windows. It allows a user to call from one PC to another on a local area network, using SIP/SDP/RTP with Ulaw encoding for voice.

真正可用的jain.jar，网上找到的很多都是假的，java上的SIP开发必备jar包-Really usable jain.jar, many find online are fake, java jar on the development of the necessary SIP package