EXHIBIT 21.01 SUBSIDIARIES Concord Communications Securities Corporation 600 Nickerson Road Marlborough, MA 01752 State of incorporation: Massachusetts Concord Communications International, Inc. 600 Nickerson Road Marlborough, MA 01752 State of incorporation: Delaware CCA Holdings, Inc. 600 Nickerson Road Marlborough, MA 01752 State of incorporation: Delaware FirstSense Software, Inc. 600 Nickerson Road Marlborough, MA 01752 State of incorporation: Delaware Concord Communications FSC, Ltd. 600 Nickerson Road Marlborough, MA 01752 Organized under the laws of: Bermuda Concord Communications (Asia Pacific) Pty, Ltd. Level 7 53 Walker Street N, Sydney 2060 Australia Organized under the laws of: Australia