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                                                                   EXHIBIT 10.16

DRAFT  (Americas) 1/12/00 (Rev 1)              SUPPORT AND MAINTENANCE AGREEMENT

     This Support and Maintenance Agreement ("Agreement") is entered into and is
effective as of the ____ day of _______________2000 (the "Effective Date") by
and between XACCT Technologies, Inc., a Delaware corporation ("XACCT") with its
principal place of business at 2900 Lakeside Drive, Suite 100, Santa Clara,
California 95054 and ________________________________, a
_______________corporation ("Licensee") with its principal place of business at
_________________________________.

This Agreement sets forth the terms and conditions under which XACCT will
provide Product Maintenance (as defined below) and Support Services (as defined
below) for the Product which is licensed by Licensee pursuant to XACCT's End
User Software License Agreement ("License Agreement"). Except where superseded
by this Agreement, all other terms and conditions of the License Agreement are
incorporated by reference. Capitalized terms that are not defined in Section 1.
below or elsewhere in this Agreement have the same meaning as in the License
Agreement.

1.       DEFINITIONS

1.1      "Designated Support Contact " means Licensee's employee who is
         authorized to contact the XACCT
          support center.

1.2      "Incident" means a single, discrete, malfunction or other problem which
         may require more than one (1) response before it is closed.

1.3      "Major Release" means a version of the Product containing significant
         changes in functionality which usually will be designated with a whole
         number product version change such as 3.x to 4.x.

1.4      "Minor Release" means a version of the Product containing minor
         improvements which usually will be designated with a one (1) decimal
         version change such as 3.x to 3.x; also sometimes referred to as "dot
         releases."

1.5      "Product Maintenance" means the Product updates and revisions that are
         available from XACCT and selected by Licensee, as further referenced
         herein and the attachments hereto as may be amended from time to time.

1.6      "Support Services" means the software support services that are
         available from XACCT and selected by Licensee, as further referenced
         herein and the attachments hereto as may be amended from time to time.

2.       COVERAGE AND PAYMENT OF FEES

         Licensee may purchase the level of Product Maintenance and Support
         Services set forth in Attachment 1 to this Agreement. XACCT will
         provide the Product Maintenance and Support Services purchased by
         Licensee subject to the terms and conditions of this Agreement and the
         License Agreement. Fees shall be payable within thirty (30) days of
         invoice which shall be exclusive of any applicable local, state,
         federal, use, excise, value added, GST or other taxes imposed on the
         fees payable for the Product Maintenance and Support Services which
         shall be the responsibility of Licensee.

3.       SUPPORT SERVICES

3.1      XACCT will provide reasonable commercial efforts to provide the
         appropriate solutions for reported Incidents. Initial response times
         for reported Incidents are as set forth in Attachment 1.

3.2      In order for Licensee to receive the Support Services referenced above,
         Licensee must:

         (a)      Appoint Designated Support Contact(s), trained and qualified,
                  who will maintain the integrity of the Product and who will
                  act as Licensee's liaison for all technical communications
                  with XACCT. The number of Designated Support Contact(s) will
                  be determined by the level of Support Services purchased by
                  Licensee set forth in Attachment 1referenced in Section 2.
                  Names of Designated Support Contact(s) must be provided to
                  XACCT prior to initial contact with the XACCT support center.
                  All technical communications by Licensee to XACCT shall only
                  be made by the Designated Support Contact(s). All information
                  and materials provided to Licensee by XACCT pursuant to this
                  Agreement will be routed to the Designated Support Contact(s).
                  Licensee may change the Designated Support Contact(s) upon
                  written notice to XACCT;


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         (b)      Promptly obtain training on the use of the Product for the
                  Designated Support Contact(s), and any other employee
                  substituting or replacing the Designated Support Contact(s);

         (c)      Subject to Licensee's applicable security requirements,
                  provide XACCT with access to and use of all information and
                  system facilities including but not limited to a modem
                  connection to Licensee's systems determined necessary by XACCT
                  to provide timely Support Services pursuant to this Agreement;

         (d)      Follow operating instructions and procedures as specified in,
                  but not limited to, XACCT's documentation and other
                  correspondence related to the Product;

         (e)      Follow procedures and recommendations provided by the XACCT
                  support center in an effort to correct problems; or

         (f)      Notify XACCT of a malfunction or other problem in accordance
                  with XACCT's then current problem reporting procedures and as
                  provided in Attachment 1. If XACCT determines that a problem
                  reported by Licensee is not due to an error in the Product,
                  XACCT will so notify Licensee. XACCT may in its sole
                  discretion charge additional fees for time and materials for
                  the resolution of problems that are not attributable to an
                  error in the Product or which are excluded from XACCT's
                  support obligations as set forth below.

3.5      XACCT shall have no obligation to support:

         (a)      altered, damaged or Licensee-modified Product, or any portion
                  of the Product incorporated with or into other software other
                  than as contemplated by XACCT's documentation or as otherwise
                  expressly approved by XACCT in writing;

         (b)      any version of the Product other than the current version of
                  the Product, the immediately previous version and the version
                  preceding the immediately previous version; XACCT's obligation
                  to support the version prior to the immediately previous
                  version shall not extend beyond six (6) months after the
                  release of the current Major Release of the Product;

         (c)      Product problems caused by Licensee's negligence, abuse or
                  misapplication, use of Product other than as specified in the
                  XACCT documentation, or other causes beyond the reasonable
                  control of XACCT;

         (d)      Product installed on any hardware, operating system version or
                  network environment that is not supported by XACCT; or

         (e)      Incidents if XACCT makes a good faith determination that the
                  primary cause of the problem results from the failure or
                  malfunction of any system, equipment, facilities or devices
                  not furnished by XACCT.

3.6      Any obligation for Support for non-standard versions of the Product or
         portions thereof developed for Licensee on a customized basis shall be
         only as set forth in an amendment or other supplement to this
         Agreement.

4.       PRODUCT MAINTENANCE

4.1      XACCT will use reasonable commercial efforts to provide maintenance
         releases and Minor Releases to the then-current embodiment of the
         Product that it provides to its customers generally. Maintenance
         Releases and Minor Releases may also include one copy of revisions to
         the documentation applicable to such maintenance releases and Minor
         Releases.


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4.2      From time to time XACCT in its sole discretion may develop and provide
         Major Releases which will be made available to Licensee with or without
         additional fees according to the level of Support Services purchased by
         Licensee as set forth in Attachment 1 referenced in Section 2.

4.3      THE TERMS OF THE LICENSE AGREEMENT PERTAINING TO LIMITED WARRANTY,
         DISCLAIMERS OF WARRANTY AND LIMITATION OF LIABILITY SHALL APPLY TO THE
         MAJOR AND MINOR RELEASES OF PRODUCT DELIVERED ACCORDING TO THIS
         AGREEMENT.

5.       TERM AND TERMINATION

5.1      The initial term of this Agreement is one (1) year from the date of
         delivery of the Product to Licensee unless earlier terminated in
         accordance with this Agreement. The Agreement will be automatically
         renewed for additional one (1) year terms (subject to applicable fee
         adjustments) unless thirty (30) days prior to the anniversary of the
         Effective Date Licensee gives written notice to XACCT of its intention
         not to renew.

5.2      XACCT may suspend or terminate Product Maintenance and Support Services
         if Licensee fails to timely pay Product Maintenance and Support Service
         fees as provided in this Agreement. XACCT may also terminate Support
         Services if Licensee breaches any provision of this Agreement or the
         License Agreement and such breach is not remedied within thirty (30)
         days after Licensee receives written notice of the breach. XACCT shall
         also have the right not to renew this Agreement with respect to any
         Product by providing written notice of such election at least sixty
         (60) days prior to the termination of Support Services for such
         Product, provided that XACCT no longer generally provides Support
         Services for such Product, or no longer provides the specific Support
         Services previously offered.

5.3      Product Maintenance and Support Services shall automatically terminate
         upon termination of the License Agreement.

6.       REINSTATEMENT OR RENEWAL OF PRODUCT MAINTENANCE AND SUPPORT SERVICES

         In the event Product Maintenance and Support Services are terminated by
         Licensee by notice of non-renewal, Product Maintenance and Support
         Services shall be discontinued at the end of the then current term. If
         Product Maintenance and Support Services are terminated for any reason,
         at XACCT's sole option, Licensee may reinstate or renew Product
         Maintenance and Support Services by paying XACCT all applicable Product
         Maintenance and Support Services and reinstatement fees.

7.       LIMITATION OF LIABILITY

7.1      Direct Damages. XACCT'S SOLE LIABILITY AND LICENSEE'S EXCLUSIVE REMEDY
         FOR DAMAGES WITH RESPECT TO THE SUPPORT SERVICES UNDER ANY CONTRACT,
         TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHER THEORY, SHALL BE
         LIMITED TO THE AMOUNT PAID BY LICENSEE FOR THE SUPPORT SERVICES FOR THE
         PRIOR 12 MONTHS. XACCT'S SOLE LIABILITY AND LICENSEE'S EXCLUSIVE REMEDY
         FOR DAMAGES WITH RESPECT TO PRODUCT MAINTENANCE SHALL BE AS SET FORTH
         IN THE LICENSE AGREEMENT.

7.2      Consequential Damages. UNDER NO CIRCUMSTANCES, INCLUDING NEGLIGENCE,
         SHALL XACCT BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL
         DAMAGES INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOST PROFITS, LOSS
         OF DATA, OR COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
         ARISING IN ANY WAY OUT OF THIS AGREEMENT OR THE USE OF THE PRODUCT AND
         DOCUMENTATION EVEN IF XACCT HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
         DAMAGES OR LOSSES.

8.       GENERAL

         This Agreement, the attachments and the License Agreement constitute
         the entire agreement between the parties regarding Product Maintenance
         and Support Services and supersede all previous agreements or


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         representations, oral or written, regarding the subject matter. This
         Agreement may not be modified or amended except in a writing signed by
         a duly authorized representative of each party. Both parties
         acknowledge having read the terms and conditions set forth in this
         Agreement and attachments hereto, understand all terms and conditions,
         and agree to be bound thereby. The laws of the State of California
         shall govern all issues arising under or relating to this Agreement,
         without giving effect to the conflict of laws principles thereof. All
         disputes arising under or relating to this Agreement shall be resolved
         exclusively in the appropriate state court in Santa Clara County,
         California or in the federal court in the Northern District of
         California, and it is explicitly agreed that no other court shall have
         such jurisdiction. This Agreement shall not be governed by the United
         Nations Convention on Contracts for the International Sale of Goods

IN WITNESS  WHEREOF,  the parties  have caused this  Agreement to be executed by
their duly authorized representatives:

LICENSEE                                  XACCT TECHNOLOGIES, INC.

By:                                       By:
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Name:                                     Name:
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Title:                                    Title:
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Date:                                     Date:
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