WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

  

<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
FINANCIAL STATEMENTS OF CONCORD COMMUNICATIONS, INC. AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1
<CURRENCY> U.S. DOLLARS
       
                                                  
<PERIOD-TYPE>                   YEAR                    6-MOS
<FISCAL-YEAR-END>                          DEC-28-1996             DEC-31-1997
<PERIOD-START>                             DEC-31-1995             DEC-29-1996
<PERIOD-END>                               DEC-28-1996             JUN-30-1997
<EXCHANGE-RATE>                                      1                       1
<CASH>                                       1,663,896               1,872,727
<SECURITIES>                                         0                       0
<RECEIVABLES>                                2,483,255               1,981,180
<ALLOWANCES>                                   210,000                 280,000
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                             4,086,085               3,667,124
<PP&E>                                       5,455,725               5,881,472
<DEPRECIATION>                               3,957,519               4,188,704
<TOTAL-ASSETS>                               5,584,291               5,585,789
<CURRENT-LIABILITIES>                        5,473,530               6,134,547
<BONDS>                                        667,502                 859,535
<PREFERRED-MANDATORY>                       14,477,729              14,919,286
<PREFERRED>                                          0                       0
<COMMON>                                         8,445                   9,095
<OTHER-SE>                                (15,042,915)            (16,336,674)
<TOTAL-LIABILITY-AND-EQUITY>                 5,584,291               5,585,789
<SALES>                                      7,844,523               6,889,982
<TOTAL-REVENUES>                             9,006,765               7,701,385
<CGS>                                        1,956,889               1,279,495
<TOTAL-COSTS>                                1,956,889               1,279,495
<OTHER-EXPENSES>                            12,150,083               7,346,413
<LOSS-PROVISION>                                80,000                  70,000
<INTEREST-EXPENSE>                              48,564                  42,886
<INCOME-PRETAX>                            (5,054,863)               (966,417)
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                        (5,054,863)               (966,417)
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                               (5,054,863)               (966,417)
<EPS-PRIMARY>                                        0                       0
<EPS-DILUTED>                                        0                       0