Exhibit 10.6

                                JOINDER AGREEMENT


              THIS JOINDER IN SUBSIDIARY  GUARANTEE,  MASTER SECURITY AGREEMENT,
STOCK PLEDGE AGREEMENT AND SECURITY AGREEMENT (this "JOINDER") is executed as of
April 13, 2006 by Network  System  Technologies,  Inc., an Illinois  corporation
("JOINING  PARTY"),  and delivered to Laurus Master Fund, Ltd., a Cayman Islands
company (the "Purchaser"). Except as otherwise defined herein, terms used herein
and defined in the 2006 Purchase Agreement (as defined below).


                              W I T N E S S E T H:
                               - - - - - - - - - -


              WHEREAS,  Incentra  Solutions,  Inc.,  a Nevada  corporation  (the
"Company"),  certain  Subsidiaries  of the Company (in the case of the  Security
Agreement)  and the  Purchaser,  have  entered  into (x) a  Securities  Purchase
Agreement,  dated as of May 13, 2004 (as amended,  modified or supplemented from
time to time, the "2004 PURCHASE AGREEMENT"), (y) a Security Agreement, dated as
of February 6, 2006 (as amended, modified or supplemented from time to time, the
"2006 SECURITY AGREEMENT") and (z) a Securities Purchase Agreement,  dated as of
the date hereof (as amended,  modified or  supplemented  from time to time,  the
"2006 PURCHASE AGREEMENT"); and

              WHEREAS,  the Joining Party is a direct or indirect  Subsidiary of
the Company and desires,  or is required  pursuant to the  provisions of each of
the 2004 Purchase  Agreement,  the 2006 Security Agreement and the 2006 Purchase
Agreement,  to become a  "Guarantor"  under the 2006  Subsidiary  Guarantee,  an
"Assignor" under the 2004 Master Security Agreement,  a "Pledgor" under the 2006
Stock  Pledge  Agreement  and  an  "Eligible   Subsidiary"  under  the  Security
Agreement;

              NOW,  THEREFORE,  in  consideration  of the  foregoing  and  other
benefits accruing to the Joining Party, the receipt and sufficiency of which are
hereby   acknowledged,   the   Joining   Party   hereby   makes  the   following
representations  and warranties to the Purchaser and hereby covenants and agrees
with the Purchaser as follows:


              NOW, THEREFORE, the Joining Party agrees as follows:

              1.     By  this   Joinder,   the  Joining   Party  becomes  (i)  a
"Guarantor"  for all  purposes  under  the 2006  Subsidiary  Guarantee,  (ii) an
"Assignor" for all purposes under the 2004 Master  Security  Agreement,  (iii) a
"Pledgor"  for all purposes  under the 2006 Stock Pledge  Agreement  and (iv) an
"Eligible Subsidiary" under the 2006 Security Agreement.

              2.     The Joining Party agrees that,  upon its execution  hereof,
it will  become a  Guarantor  under,  and as  defined  in,  the 2006  Subsidiary
Guarantee  with respect to all  Obligations  (as defined in the 2006  Subsidiary
Guarantee),  and will be bound by all terms, conditions and duties applicable to
a Guarantor  under the 2006  Subsidiary  Guarantee.  Without  limitation  of the
foregoing,  and in furtherance  thereof,  the Joining Party  unconditionally and



                                                                          Page 2

irrevocably,  guarantees  the due and punctual  payment and  performance  of all
Obligations (on the same basis as the other Guarantors under the 2006 Subsidiary
Guarantee).

              3.     The Joining Party agrees that,  upon its execution  hereof,
it will  become a Pledgor  under,  and as  defined  in,  the 2006  Stock  Pledge
Agreement, and will be bound by all terms, conditions and duties applicable to a
Pledgor  under  the 2006  Stock  Pledge  Agreement.  Without  limitation  of the
foregoing  and in  furtherance  thereof,  as security  for the due and  punctual
payment of the Indebtedness (as defined in the 2006 Stock Pledge Agreement), the
Joining Party hereby pledges,  hypothecates,  assigns,  transfers, sets over and
delivers to the Purchaser and grants to the Purchaser a security interest in all
Collateral  (as defined in the 2006 Stock Pledge  Agreement),  if any, now owned
or,  to the  extent  provided  in the 2006  Stock  Pledge  Agreement,  hereafter
acquired by it.

              4.     (x) The  Joining  Party  agrees  that,  upon its  execution
hereof,  it will  become an Assignor  under,  and as defined in, the 2004 Master
Security  Agreement,  and will be  bound by all  terms,  conditions  and  duties
applicable  to an Assignor  under the 2004 Master  Security  Agreement.  Without
limitation of the foregoing and in furtherance  thereof, as security for the due
and punctual  payment of the Obligations (as defined in the 2004 Master Security
Agreement), the Joining Party hereby pledges, hypothecates,  assigns, transfers,
sets over and delivers to the  Purchaser  and grants to the Purchaser a security
interest in all Collateral (as defined in the 2004 Master  Security  Agreement),
if any,  now  owned or,  to the  extent  provided  in the 2004  Master  Security
Agreement, hereafter acquired by it.

              (y)    The Joining Party agrees that,  upon its execution  hereof,
it will  become an  Eligible  Subsidiary  under,  and as  defined  in,  the 2006
Security  Agreement,  and will be  bound by all  terms,  conditions  and  duties
applicable to an Eligible Subsidiary under the 2006 Security Agreement.  Without
limitation of the foregoing and in furtherance  thereof, as security for the due
and punctual payment of the Obligations (as in the 2006 Security Agreement), the
Joining Party hereby pledges,  hypothecates,  assigns,  transfers, sets over and
delivers to the Purchaser and grants to the Purchaser a security interest in all
Collateral (as defined in the 2006 Security Agreement), if any, now owned or, to
the extent provided in the 2006 Security Agreement, hereafter acquired by it.

              5.     In connection with the grant by the Joining Party, pursuant
to paragraphs 3 and 4 above, of a security  interest in all of its right,  title
and interest in the Collateral  (as defined in each of the 2004 Master  Security
Agreement,  the 2006 Security  Agreement and the 2006 Stock Pledge Agreement) in
favor  of the  Purchaser,  the  Joining  Party  (i)  agrees  to  deliver  to the
Purchaser,  together  with  the  delivery  of this  Joinder,  each of the  items
specified  in  Section 3 of the 2006  Stock  Pledge  Agreement,  (ii)  agrees to
execute (if necessary)  and deliver to the Purchaser such financing  statements,
in form  acceptable  to the  Purchaser,  as the  Purchaser may request or as are
necessary or desirable in the opinion of the Purchaser to establish and maintain
a  valid,  enforceable,  first  priority  perfected  security  interest  in  the
Collateral (as defined in each of the 2004 Master Security  Agreement,  the 2006
Security  Agreement  and the 2006 Stock Pledge  Agreement)  owned by the Joining
Party,  (iii)  authorizes  the Purchaser to file any such  financing  statements
without  the  signature  of the  Joining  Party  where  permitted  by law  (such
authorization  includes a description  of the  Collateral as "all assets and all
personal property,  whether now owned and/or hereafter  acquired" of the Joining
Party all assets and all personal



                                                                          Page 3

property,  whether now owned and/or  hereafter  acquired" (or any  substantially
similar  variation  thereof))  and (iv)  agrees to  execute  and  deliver to the
Purchaser  assignments of United States trademarks,  patents and copyrights (and
the respective applications therefor) to the extent requested by the Purchaser.

              6.     Without  limiting the  foregoing,  the Joining Party hereby
makes and  undertakes,  as the case may be, each  covenant,  representation  and
warranty  made by, and as (i) each  Guarantor  pursuant  to the 2006  Subsidiary
Guarantee,  (ii) each Assignor  pursuant to the 2004 Master Security  Agreement,
(iii) each  Pledgor  pursuant to the 2006 Stock Pledge  Agreement  and (iv) each
Eligible Subsidiary pursuant to the 2006 Security Agreement,  in each case as of
the date  hereof  (except  to the  extent any such  representation  or  warranty
relates solely to an earlier date in which case such representation and warranty
shall be true and correct as of such  earlier  date),  and agrees to be bound by
all covenants,  agreements and obligations of a Guarantor, Assignor, Pledgor and
Eligible  Subsidiary  pursuant  to the 2006  Subsidiary  Guarantee,  2004 Master
Security Agreement, 2006 Stock Pledge Agreement and the 2006 Security Agreement,
respectively,  and all other Related  Agreements (as defined in each of the 2004
Purchase Agreement and the 2006 Purchase Agreement) and/or Ancillary  Agreements
(as defined in the 2006 Security Agreement) to which it is or becomes a party.

              8.     Schedule A to the 2006  Stock  Pledge  Agreement  is hereby
amended by  supplementing  such  Schedule with the  information  for the Joining
Party contained on Schedule A attached hereto as Annex I. In addition,  Schedule
A to the Master  Security  Agreement  is hereby  amended by  supplementing  such
Schedule  with the  information  for the Joining  Party  contained on Schedule A
attached hereto as Annex II.

              9.     This Joinder  shall be binding upon the parties  hereto and
their respective successors and permitted assigns and shall inure to the benefit
of and be  enforceable  by each of the  parties  hereto and its  successors  and
permitted assigns, PROVIDED, HOWEVER, no Joining Party may not assign any of its
rights,  obligations or interest hereunder or under the 2004 Purchase Agreement,
the 2006 Security  Agreement,  the 2006 Purchase Agreement or, in each case, any
agreement related thereto, without the prior written consent of the Purchaser by
such agreement.  THIS JOINDER SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH
AND  GOVERNED BY THE LAW OF THE STATE OF NEW YORK.  This Joinder may be executed
in any number of  counterparts,  each of which shall be an original,  but all of
which shall  constitute one instrument.  In the event that any provision of this
Joinder  shall prove to be invalid or  unenforceable,  such  provision  shall be
deemed to be severable  from the other  provisions  of this Joinder  which shall
remain binding on all parties hereto.

              10.    From and after the  execution  and  delivery  hereof by the
parties hereto,  this Joinder shall constitute (I) a "Related Agreement" for all
purposes of (x) the 2004 Purchase Agreement and the Related Agreements  referred
to in the 2004 Purchase Agreement, as each are amended, modified or supplemented
from time to time and (y) the 2006 Purchase Agreement and the Related Agreements
referred to in the 2006  Purchase  Agreement,  as each are amended,  modified or
supplemented  from  time  to time  and  (II) an  "Ancillary  Agreement"  for all
purposes of the 2006 Security Agreement and the Ancillary Agreements referred to
in the 2006 Security Agreement, , as each are amended,  modified or supplemented
from time to time.

              11.    The effective date of this Joinder is March 31, 2006.


                                      * * *

                                                                          Page 4


              IN WITNESS  WHEREOF,  the Joining Party has caused this Joinder to
be duly executed as of the date first above written.


                                        NETWORK SYSTEM TECHNOLOGIES, INC.




                                        By:  /s/ Thomas P. Sweeney III
                                             -------------------------
                                             Name:  Thomas P. Sweeney III
                                             Title: Chief Executive Officer




                                                                          Page 5


Accepted and Acknowledged by:

LAURUS MASTER FUND, LTD.



By:   /s/ David Grin
     -----------------------------
     Name:  David Grin
     Title:  Director