EXHIBIT 3.5

                          THIRD AMENDMENT TO BYLAWS OF
                           COSINE COMMUNICATIONS, INC.
                             A Delaware Corporation

THE FOLLOWING AMENDMENT TO THE BYLAWS OF COSINE COMMUNICATIONS, INC., A DELAWARE
CORPORATION, WAS ADOPTED BY THE BOARD OF DIRECTORS ON FEBRUARY, 2004:

         ARTICLE 3.2

         Article 3.2 was amended to read in its entirety as follows:


         3.2      NUMBER OF DIRECTORS

                  The authorized number of directors shall be four (4). This
         number may be changed by a duly adopted resolution of the board of
         directors.

                  No reduction of the authorized number of directors shall have
         the effect of removing any director before that director's term of
         office expires.

                  A class of directors shall be elected at each annual meeting
         of stockholders as provided in Section 3.3 of these bylaws. Each
         director, including a director elected to fill a vacancy, shall hold
         office until the earlier of their death, resignation or expiration of
         the term for which elected and until a successor has been elected and
         qualified.