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                                                                   Exhibit 10.6C

                                 PROMISSORY NOTE

$300,000.00                                                     January 13, 2000



         FOR VALUE RECEIVED, the undersigned hereby promises to pay to Verilink
Corporation ("Verilink") at Huntsville, Alabama, the principal amount of Three
Hundred Thousand Dollars ($300,000.00). All principal due under this Note shall
be paid on the earlier of (i) termination of the undersigned's employment by
Verilink for any reason provided, however that for purposes of this paragraph
(i), the principal balance of this Note will be reduced by 25% each full year
that the undersigned remains employed by Verilink; or (ii) within one (1) year
after the value of the undersigned's exercisable Verilink stock options exceed
$2,000,000 (fair market value of stock subject to exercisable options less total
exercise price of such options). Interest shall be forgiven.

         This Note may be prepaid at any time, in whole or in part, without
premium or penalty.

         If action should be instituted on this Note, the undersigned agrees to
pay the holder, in addition to such amounts owed pursuant to this Note, all
costs of collection, including a reasonable sum of attorney's fees.

         This Promissory Note shall be governed by the laws of the State of
Alabama.




                                               /s/ Graham G. Pattison
                                        -----------------------------------
                                                 Graham G. Pattison