Storage technology has enjoyed considerable growth since the first disk drive was introduced nearly 50 years ago. Various storage devices with large volume and high performance are emerging and they carry the important information for our social life. How to make the devices more broadly and effectively used and make the information more available is a problem for today. IP-based Storage provides such a cheap interface for storage devices under the rapid development of network technology. This paper answers what is network storage relative to traditional storage and then puts emphasis on two typical IP-based storage technologies NAS and iSCSI. The article evaluates the performance of NAS and iSCSI by measuring and analyzing file-level access performance and block-level access performance. Our test results show that iSCSI provides higher performance then using NFS protocol in Linux or SMB protocol in Windows (NAS scheme). The last part of the paper gives characteristic and trade-off of several IP-based storage system architectures.