EXHIBIT 21 NETRIX International Corporation, Delaware NETRIX GmbH, Germany NETRIX S.r.l., Italy NETRIX (Australia) Pty Limited, Australia OpenROUTE Networks, Inc. Subsidiaries of the registrant: I. Proteon International Ltd. Lockington Hall Derby DE74 2RH England Organized under the laws of England II. Proteon International SARL 2000 route des Lucioles Les Algorithmes Bat Aristote A-BP 29 Sophia Antipolis 06901 France Organized under the laws of France III. Proteon International GMBH Falkensteiner Strasse 11 Kelkheim D 65779 Germany Incorporated under the laws of Germany IV. OpenROUTE Networks (S) Pte Ltd. 491B River Valley Road #14-03 Valley Point Office Tower Singapore 248373 Organized under the laws of Singapore V. Proteon, Inc. Nine Technology Drive Westborough, Massachusetts 01581-1799 USA Incorporated in the Commonwealth of Massachusetts VI. Proteon Securities Corporation Nine Technology Drive Westborough, Massachusetts 01581-1799 USA Incorporated into the Commonwealth of Massachusetts VII. Proteon Federal Systems, Inc. (Inactive) Nine Techology Drive Westborough, Massachusetts 01581-1799 USA Incorporated in the Commonwealth of Massachusetts VIII. Proteon FSC, Inc. 55-11 Curaco Gade Charlotte Amalie Virgin Islands 00803 Incorporated in the U.S. Virgin Islands IX. Proteon Australia PTY 80 Mount Street Level 8 North Sydney NSW 2060 Australia Organized under the laws of Australia