<PAGE>   1
                                                                   EXHIBIT 10.12



CONFIDENTIAL TREATMENT HAS BEEN REQUESTED FOR CERTAIN REDACTED PROVISIONS OF
THIS AGREEMENT. THE REDACTED PROVISIONS ARE IDENTIFIED BY THREE ASTERISKS
ENCLOSED BY BRACKETS AND UNDERLINED. THE CONFIDENTIAL PORTION HAS BEEN FILED
SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.










--------------------------------------------------------------------------------






                          PRODUCT PROCUREMENT AGREEMENT



                                 BY AND BETWEEN

                         CTC COMMUNICATIONS GROUP, INC.

                                       AND

                           ACCELERATED NETWORKS, INC.

                                      DATED

                                 APRIL 21, 1999







--------------------------------------------------------------------------------


<PAGE>   2


                       PRODUCT PROCUREMENT AGREEMENT (PPA)
                              FOR STRATEGIC ACCOUNT


        THIS PRODUCT PROCUREMENT AGREEMENT (PPA) FOR STRATEGIC ACCOUNT (this
"AGREEMENT"), effective as of this 21st day of April, 1999 (the "EFFECTIVE
DATE"), is made and entered into by and between ACCELERATED NETWORKS, INC., a
California corporation with its principal place of business at 301 Science
Drive, Moorpark, CA 93021 ("SELLER"), and CTC COMMUNICATIONS CORP., a
Massachusetts corporation with its principal place of business at 360 2nd
Avenue, Waltham, MA 02451 ("CUSTOMER"). CUSTOMER and SELLER are also hereinafter
referred to individually as a "PARTY" and collectively as the "PARTIES".

        WHEREAS, CUSTOMER desires to expand its network throughout the
Northeastern United States, and to facilitate such expansion, CUSTOMER wishes to
purchase from SELLER certain products (the "PRODUCT" or "PRODUCTS") more fully
described on Attachment A hereto at the discounted rates (the "DISCOUNTS") more
fully described on Attachment B hereto; and

        WHEREAS, SELLER desires to provide the Products at the Discounts to
CUSTOMER pursuant to the terms and conditions of this Agreement.

        NOW, THEREFORE, in consideration of the mutual promises contained
herein, and other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the Parties, intending to be legally bound,
hereby agree hereto as follows:

        1. PRODUCT ORDERS.

        1.1 Initial Purchase Order. Upon execution of this Agreement, CUSTOMER
shall submit a blanket purchase order (the "INITIAL PURCHASE ORDER") for the
Products having an aggregate purchase price of at least [***]. CUSTOMER will
periodically submit purchase orders to SELLER for release of the Products
covered by the Initial Purchase Order as per the timeframes described in
Attachment B. CUSTOMER may specify the carrier and mode of transportation for
shipment of the Products. Unless specifically stated to the contrary in a
particular purchase order signed by representatives of both Parties, the terms
and conditions of this Agreement shall be controlling over any inconsistent or
conflicting terms or provisions contained in any purchase order pursuant hereto.

        1.2 Subsequent Purchase Orders. During the term of this Agreement,
CUSTOMER shall submit purchase orders in addition to the Initial Purchase Order
in order to meet the Minimum Purchase Commitment as indicated and defined on
Attachment B hereto. The terms of this Agreement shall apply to all such
subsequent purchase orders.

-------------
        *** Confidential Treatment has been requested for certain redacted
provisions of this agreement. The redacted provisions are identified by three
asterisks, enclosed by brackets and underlined. The confidential portion has
been filed separately with the Securities and Exchange Commission.



                                                                              1.
<PAGE>   3


        1.3 Submission of Orders. All purchase orders, including purchase orders
for release of the Products, shall be sent by fax to the following number
(followed by a hard copy sent by mail pursuant to Section 13.2 hereof):

        ACCELERATED NETWORKS, INC;
        ATTN:  SALES ADMINISTRATION
        FAX:  (805) 553-9690
        TEL:  (805) 553-9680

        1.4 Cancellation and Rescheduling. CUSTOMER may cancel delivery of
Products pursuant to a purchase order without charge upon written notice to
SELLER not less than [***] prior to the scheduled delivery date. CUSTOMER will
be responsible for payment of one hundred percent (100%) of the amount of any
portion of a purchase order that is canceled less than [***] prior to the
scheduled delivery date. CUSTOMER may extend the date for delivery of Products
pursuant to a purchase order [***] without charge upon written notice to SELLER
not less than [***] prior to the scheduled delivery date; provided, that, the
new delivery date is on or before the: [***].

        1.5 Pricing. Product prices payable by CUSTOMER and applicable Discounts
are set forth in Attachment B. Prices are exclusive of all taxes, customs,
duties or similar tariffs and fees, shipping and insurance charges which SELLER
may be required to pay or collect upon the sale or delivery of the Products or
upon collection of the sales price, all of which shall be CUSTOMER's
responsibility. SELLER shall promptly extend to CUSTOMER any price reductions
made by SELLER in its generally available, then current published list prices
for Software or Products. Such price reduction shall apply to all purchase
orders received on or after the effective date of such price reduction.

        1.6 Payment. Terms of payment are net thirty (30) days of CUSTOMER's
receipt of SELLER's invoice, unless CUSTOMER fails to pay within thirty (30)
days of receipt of SELLER's invoice three (3) times within any twelve (12) month
period, in which case payment terms shall be, at SELLER's election, cash on
delivery (C.O.D.), in advance of delivery or by irrevocable letter of credit in
favor of SELLER. All payments shall be made in U.S. dollars in the United
States. The payment date shall be deemed the date that CUSTOMER initiates the
wire transfer or the date CUSTOMER mails the payment pursuant to the
requirements of Section 13.2.

        2. DELIVERY AND ACCEPTANCE.

        2.1 Delivery. Products shall be delivered free on board (FOB) SELLER's
facility or other place of shipment. Shipments will be made to the delivery
address specified on CUSTOMER's purchase order. In the absence of a specified
delivery address on the purchase order, delivery will be made to CUSTOMER's
facility, or any other standard location designated by CUSTOMER Shipping
arrangements shall be mutually agreed upon by the Parties prior to

-------------
        *** Confidential Treatment has been requested for certain redacted
provisions of this agreement. The redacted provisions are identified by three
asterisks, enclosed by brackets and underlined. The confidential portion has
been filed separately with the Securities and Exchange Commission.



                                                                              2.
<PAGE>   4

delivery. SELLER shall use its best efforts to fill CUSTOMER's orders up to the
committed units on Attachment B within [***] of receiving a purchase order, and
shall use its commercially reasonable efforts to fill (by full or partial
shipment) CUSTOMER's purchase orders for Products in excess of those indicated
on Attachment B within [***] of receiving a purchase order.

        2.2 Inspection and Acceptance of Deliveries. CUSTOMER shall have the
right to visually inspect all Products ordered pursuant to this Agreement for a
period of [***] following receipt of delivery. If any delivered Product fails to
conform to the applicable purchase order or release, in whole or in part,
CUSTOMER may reject the delivery and CUSTOMER shall promptly return the rejected
Product(s) to SELLER at SELLER's risk and expense. Promptly following SELLER's
general release of Software (as defined below) SELLER will provide CUSTOMER with
a reasonable number of copies of such Software release for the sole purpose of
performing acceptance testing during the [***] following receipt of the
applicable Software copies (the "ACCEPTANCE TEST PERIOD"). If any Software, or
portion thereof, is determined by CUSTOMER during the Acceptance Test Period to
fail to conform to the applicable specifications in any material adverse way,
then CUSTOMER may reject the delivery and CUSTOMER shall promptly return the
rejected Software to SELLER at SELLER's risk and expense. CUSTOMER shall notify
SELLER if such Software release fails to conform to the applicable
specifications in any materially adverse way, specifying in reasonable detail so
as to permit SELLER to reproduce the failures. CUSTOMER's failure to notify
SELLER of any such failure of the Software release before the end of the
applicable Acceptance Test Period shall be deemed acceptance of Software
release. Upon receipt of the rejected Product(s), or Software SELLER shall
promptly ship replacement Product(s) or Software to CUSTOMER, at SELLER's risk
and expense until Product(s) or Software is reasonably determined by CUSTOMER to
be satisfactory as per applicable specifications. CUSTOMER shall have the right
to test the replacement Product(s), including the Software, as provided above in
this Section 2.2. SELLER shall ship the remaining portion of the order within
five (5) business days of the earlier of the date such CUSTOMER notifies SELLER
of its acceptance of the Software or the date CUSTOMER is deemed to have
accepted such Software.

        2.3 Pre-shipment Review. If requested by CUSTOMER, a representative of
CUSTOMER may participate, to the extent applicable, in SELLER's preshipment
configuration, prestaging and inspection of Products at SELLER's facility or any
reasonable location where Products are held or stored as determined by SELLER.

-------------
        *** Confidential Treatment has been requested for certain redacted
provisions of this agreement. The redacted provisions are identified by three
asterisks, enclosed by brackets and underlined. The confidential portion has
been filed separately with the Securities and Exchange Commission.



                                                                              3.
<PAGE>   5

        3. SOFTWARE LICENSE.

        3.1 License Grant. SELLER grants CUSTOMER, subject to the terms and
conditions set forth in this Agreement, a non-exclusive, non-transferable,
non-sublicensable perpetual license to use the software, including any
enhancements, upgrades, and patches, used in connection with or comprising any
Product (including software contained in firmware embedded in a Product) (the
"SOFTWARE"). All copies of the Software are licensed and not sold. As between
the Parties, SELLER retains all title to (except as expressly licensed by
SELLER), and rights (including all intellectual property and proprietary rights
anywhere in the world) and interest in the Software.

        3.2 License Restrictions. CUSTOMER shall not, and shall use commercially
reasonable efforts to deter others from, (i) copying, modifying, distributing,
or creating any derivative work of the Software or including the Software in any
other software, (ii) deleting, altering or obscuring any copyright or other
notice or proprietary legend appearing in the Software or on any documentation,
media, master or package materials for the Software provided by SELLER or (iii)
reverse assembling, decompiling, reverse engineering (except to the extent
permitted by applicable law) or otherwise attempting to derive the source code
(or the underlying ideas, structure, sequence, organization or algorithms) from
the Software.

        3.3 Liability for Infringement. SELLER shall defend CUSTOMER against any
suit, claim, proceeding or threatened suit brought against CUSTOMER alleging
that the licensing to, or use by CUSTOMER of, any Software or Product furnished
hereunder infringes any patent ("INFRINGEMENT CLAIM"). SELLER shall pay all
litigation costs, reasonable attorneys' fees, settlement payments and damages
awarded or resulting from any such suit, claim, or proceeding provided, that,
CUSTOMER (i) notifies SELLER in writing within a reasonable time of its actual
knowledge of any such claim, suit, or proceeding; (ii) gives SELLER the right to
control or direct the investigation, preparation, defense and settlement of any
claim, suit or proceeding related thereto; and (iii) gives SELLER reasonable
assistance and cooperation for the defense or settlement thereof. SELLER shall
not be liable for, and CUSTOMER shall defend, indemnify and hold SELLER harmless
in respect of, any suit, claim, proceeding or threatened suit and all litigation
costs, reasonable attorneys' fees, settlement payments and damages awarded or
resulting from any claim, suit or proceeding based on (i) CUSTOMER's willful,
knowing, or deliberate infringement of a patent, copyright, trade secret,
trademark or other proprietary right; (ii) any Software, Product or portion
thereof (a) not supplied by SELLER to CUSTOMER or directed by SELLER that
CUSTOMER purchase, (b) designed in accordance with CUSTOMER's specifications, or
to the extent the infringement results from compliance with such specifications,
(c) modified by CUSTOMER, to the extent the infringement results from such
modification, (d) combined with other products, processes or materials not
supplied, specified or distributed by SELLER, to the extent the infringement
results from such combination, (e) where CUSTOMER continues allegedly infringing
activity after being notified thereof and after being provided with a
non-infringing modification or workaround that would have avoided the alleged
infringement, or (f) where CUSTOMER's use of the Software or Product is incident
to an infringement not resulting primarily from such Software or Product or is
intentionally outside the scope of the license granted in Section 3.1. Neither
Party may enter into any settlement or other agreement without prior written
consent of the other Party under which such other Party would be obligated to
make any payment or incur any liability. If any Software



                                                                              4.
<PAGE>   6

or any Product becomes, or in SELLER's reasonable opinion is likely to become,
the subject of an infringement claim, SELLER, in addition to providing
indemnity, may at SELLER's option (i) procure for CUSTOMER the right to continue
using the alleged infringing Software or Product; (ii) replace or modify the
same with equivalent or better Software or Product so that CUSTOMER's use is
non-infringing; or (iii) accept return of the affected portion of the Software
or Product and refund to CUSTOMER the depreciated value of the Software or
Product so returned (as amortized on a straight-line basis over three (3) years
from the Effective Date).

        4. MONTHLY MEETINGS. SELLER and CUSTOMER shall each designate one
representative to serve as a liaison with the other Party (each, a
"REPRESENTATIVE" and collectively the "REPRESENTATIVES"). The Representatives
will meet, either in person or by telephone, to discuss in good faith matters
relating to this Agreement including Product delivery schedules, joint marketing
activities, sales training needs, price changes, review of the forecast and new
Product features and enhancements. Such meetings will take place on a monthly
basis at a mutually agreed upon location. Each Party shall bear its own costs
incurred in attending or participating in such meetings.

        5. SELLER'S WARRANTY.

        5.1 Product Warranty. SELLER warrants to CUSTOMER (i) For a period of
one (1) year from the date of acceptance, that the hardware Products shall be
free from material defects in materials and workmanship; (ii) for a period of
ninety (90) days from the date of acceptance, any existing Software shall
perform in accordance with applicable specifications in all material respects
identified in the user manual of the then current release and any new or
specially developed software or Product shall perform in accordance with
mutually agreeable documented specifications in all material respects; and (iii)
services performed by SELLER hereunder shall be performed in a professional and
workmanlike manner and in accordance with current industry standards. SELLER's
warranty does not extend to any Product that (a) is modified or altered by the
CUSTOMER or at the CUSTOMER's direction; (b) is not maintained to SELLER's
maintenance recommendations set forth in the applicable documentation actually
received by CUSTOMER; (c) is operated in a manner other than that specified by
SELLER, (d) has its serial number removed or altered; or (e) is treated with
abuse, negligence or other improper treatment (including, without limitation,
use outside the recommended environment).

        5.2 Remedies. Products delivered to CUSTOMER by SELLER hereunder which
do not comply With the, warranties in Sections 5.1, 5.4 or 5.5 hereof, and are
returned to SELLER during the applicable warranty period shall be repaired or
replaced at SELLER's option, at no cost to CUSTOMER. Subject to Section 10.4
hereof, if SELLER cannot or determines that it is not practical to, repair or
replace a returned Product, the price paid by CUSTOMER for such Product will be
credited and applied to future orders.

        5.3 Disclaimer. SELLER MAKES NO WARRANTIES (OTHER THAN AS EXPRESSLY
PROVIDED IN SECTIONS 5.1, 5.4, 5.5 AND 6 HEREOF) WITH RESPECT TO THE PRODUCTS OR
ANY SERVICES, AND DISCLAIMS ALL IMPLIED WARRANTIES, INCLUDING WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. FURTHER,
SELLER DOES NOT WARRANT



                                                                              5.
<PAGE>   7

THE USE, OR THE RESULTS OF THE USE, OF THE PRODUCTS OR THAT ANY SOFTWARE WILL BE
ERROR-FREE.

        5.4 Year 2000 Compliance Warranty. SELLER represents and warrants (the
"YEAR 2000 WARRANTY") that (a) all calendar-related processing by the Products
of date data or of any system date shall not cause the Products to cease to
operate in accordance with their applicable specifications, (b) all data fields
for the date data contained in the Products are four-digit fields capable of
indicating century and millennium, and (c) that SELLER has verified through its
testing procedures that no change in the system date (including the change from
the year 1999 to the year 2000 and leap year calculations) will cause the
Products to cease to operate in accordance with their applicable specifications,
provided that, all other products and systems, including, without limitation,
hardware, software and firmware used in combination with the Products, properly
and accurately exchange date data with the Products.

        5.5 Infringement Warranty. SELLER represents and wan ants to the
CUSTOMER that, to the best of SELLER's knowledge at the time of each delivery of
Software or Products hereunder, such Software and Products do not infringe the
intellectual property rights of any third parties.

        6. OTHER REPRESENTATIONS AND WARRANTIES. The Parties represent, warrant
and covenant that (i) they shall comply with good business practices and all
laws and regulations relevant to this Agreement or the subject matter hereof;
(ii) they shall use the then current names used for the Products, provided that
all advertisements, promotional materials, packaging and anything else bearing
any trademark of the SELLER shall identify SELLER as the trademark owner of the
Products and shall be subject to SELLER's prior written approval, which approval
shall not be unreasonably withheld or delayed; (iii) they shall comply with all
export laws, restrictions, national security controls and regulations of the
United States or other applicable foreign agency or authority; and (iv) shall
not export or re-export, or allow the export or re-export of any Product or
Proprietary Information (as defined below) or any direct product thereof in
violation of any such restrictions, laws or regulations, or without all required
licenses and proper authorizations, to or from any Group D:I or E:2 country (or
national of such country) specified in the then current U.S. Export
Administration Regulations (or any successor supplement or regulations).

        7. LIMITATION OF LIABILITY. UNLESS CAUSED OR CONTRIBUTED TO BY A PARTY'S
GROSS NEGLIGENCE OR WILLFUL MISCONDUCT, NEITHER PARTY WILL BE LIABLE WITH
RESPECT TO ANY SUBJECT MATTER OF THIS AGREEMENT UNDER ANY CONTRACT, NEGLIGENCE,
STRICT LIABILITY OR OTHER LEGAL OR EQUITABLE THEORY FOR (I) ANY AMOUNTS IN
EXCESS IN THE AGGREGATE OF THE AMOUNTS PAID TO IT (IN THE CASE OF SELLER) OR (IN
THE CASE OF CUSTOMER) PAID OR OWED BY IT HEREUNDER DURING THE TWELVE (12) MONTH
PERIOD PRIOR TO DATE THE CAUSE OF ACTION AROSE, (II) ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA OR (III) COST OF PROCUREMENT OF
SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES. THE LIMITATIONS OF THIS SECTION 7
SHALL NOT APPLY TO ANY BREACH OF SECTIONS 3.2, 3.3 OR 9.



                                                                              6.
<PAGE>   8

        8. RELATIONSHIP OF THE PARTIES. The Parties expressly acknowledge that
they are independent contractors in the performance of this Agreement, and each
Party is solely liable for all labor and related expenses it incurs in
connection with this Agreement. Neither Party will have, nor will it represent
that it has, any power, right or authority to bind the other Party, or to assume
or create any obligation or responsibility, express or implied, on behalf of the
other Party.

        9. PROPRIETARY INFORMATION.

        9.1 The Parties acknowledge that in the course of performing their
duties under this Agreement, each may obtain confidential and proprietary
information of the other ("PROPRIETARY INFORMATION"). Such Proprietary
Information may include, but is not limited to, trade secrets, know-how,
inventions, techniques, processes, programs, schematics, software source code,
data, customer lists, financial information, and sales and marketing plans.
Nothing will be considered Proprietary Information unless either (i) it is or
was disclosed in tangible form and is conspicuously marked "Confidential,"
"Proprietary" or the like or (ii) it is or was disclosed in non-tangible form
and orally identified as confidential at the time of disclosure and is
summarized in tangible form conspicuously marked "Confidential," "Proprietary"
or the like within thirty (30) days of the original disclosure. Notwithstanding
the foregoing, source code of Software supplied to CUSTOMER shall be deemed
SELLER's Proprietary Information. Each Party shall at all times keep in trust
and confidence all Proprietary Information of the other Party and, during the
term of this Agreement and for three (3) years after its termination, shall not
use such Proprietary Information other than in the course of performing its
duties under this Agreement nor shall it disclose any such Proprietary
Information to any third party without the written consent of the other. Upon
termination or expiration of this Agreement or upon the request of the
disclosing Party, each Party shall promptly return all manifestations of the
other's Proprietary Information in its possession.

        9.2 Neither Party shall have an obligation to maintain the
confidentiality of information for which it can demonstrate to the reasonable
satisfaction of the disclosing Party that (a) it received rightfully from
another party without restrictions on disclosure prior to its receipt from the
disclosing Party; (b) the disclosing Party has disclosed to an unaffiliated
third party without any obligation to maintain such information in confidence;
or (c) is independently developed by the obligated Party.

        9.3 Further, the receiving Party may disclose Proprietary Information as
required by final, unappealable governmental or judicial order, provided such
Party gives the disclosing Party prompt written notice prior to such disclosure,
and complies with any protective order (or equivalent) imposed on such
disclosure, and provides the disclosing Party the option of either seeking a
protective order or having its Proprietary Information be subject to the same
protective orders as may apply to the disclosing Party's own information. Except
as otherwise provided herein, neither Party shall disclose, disseminate or
distribute any of the other Party's Proprietary Information to any third party
without the other Party's prior written permission.

        9.4 All Proprietary Information, unless otherwise specified in writing,
shall remain the property of the disclosing Party, shall be used by the
receiving Party only for the purpose intended, and such Proprietary Information,
including all copies thereof, shall be returned to the



                                                                              7.
<PAGE>   9

disclosing Party or destroyed upon the earliest to occur of (a) the written
request of the disclosing Party; or (b) the date of termination or expiration of
this Agreement. The receiving Party shall promptly provide a written
certification the disclosing Party that all Proprietary Information has been
returned or destroyed.

        9.5 Each Party agrees that, without the other Party's written consent,
it will not use the name, service marks or trademarks of the other Party or of
any of its affiliates in any advertising, publicity releases or sales
presentations. Neither Party shall take any actions which will in any manner
compromise the other Party's registered trademarks and/or service marks.

        9.6 The Parties agree that a breach of the terms of this Section 9 would
result in irreparable injury to the disclosing Party for which a remedy in
damages would be inadequate and that the disclosing Party shall be entitled to
seek injunctive relief to prevent the breach or threatened breach, in addition
to remedies otherwise available at law or in equity.

        10. TERM AND TERMINATION.

        10.1 Term. This Agreement shall commence on the Effective Date and shall
remain in force for a period of three (3) years from the date of the first
shipment unless earlier terminated as provided in this Section 10. Thereafter,
this Agreement shall automatically renew for successive one (1) year terms
unless a Party provides written notice to the other Party no later than sixty
(60) days prior to the expiration of the then current term of such Party's
intent not to renew. Notwithstanding anything to contrary contained in this
Agreement, the license granted in Section 3.1 shall survive the expiration or
any termination of this Agreement for reasons other than for breach by the
CUSTOMER of Section 3.2 or intentional violation of Section 9.

        10.2 Termination for Cause. This Agreement may be terminated by either
Party for cause immediately upon receipt of written notice upon the occurrence
of any of the following events: (i) if the other Party ceases to do business, or
otherwise terminates its business operations; provided, however, that the
acquisition of all or substantially all of a Party's stock, assets or business
shall not be grounds for termination of this Agreement; or (ii) if the other
Party breaches any material provision of this Agreement and fails to cure such
breach within thirty (30) days of receipt of written notice describing the
breach, provided, however, that a breach of any of the obligations set forth in
Section 3.2 or an intentional violation of Section 9 shall be grounds for
immediate termination of this Agreement by the non-breaching Party; or (iii) if
the other Party becomes insolvent or seeks protection under any bankruptcy,
receivership, trust deed, creditors arrangement, composition or comparable
proceeding, or if any such proceeding is instituted against the other (and not
dismissed within ninety (90) days).

        10.3 Effect of Termination. Upon any termination or expiration of this
Agreement, all pending purchase orders, including purchase orders for release of
Products under a blanket purchase order shall be canceled as of the effective
date of termination or expiration, all sums payable to SELLER shall be due and
payable on the effective date of termination or expiration and all licenses
granted to CUSTOMER under this Agreement shall immediately terminate and
CUSTOMER shall discontinue all distribution of the Products, provided, however,
that, except in the event of a breach by CUSTOMER of Section 3.2 or intentional
violation of Section 9, CUSTOMER shall be entitled to continue to use the
Products pursuant to Section 3.1.



                                                                              8.
<PAGE>   10

        10.4 If the Software or Products, or parts thereof, do not meet the
applicable specifications in any materially adverse respect at any time during
the duration of the license granted for such Software or Products, then SELLER
shall develop an action plan to cure the deficiency within seventy (70) days of
the discovery of the deficiency and deliver such action plan to CUSTOMER within
ten (10) days of SELLER's discovery, or the receipt of notice from CUSTOMER, of
the deficiency. Notwithstanding anything to the contrary contained herein, if
SELLER does not diligently pursue the action plan or the deficiency is not
corrected to the reasonable satisfaction of CUSTOMER within such seventy (70)
day period, then CUSTOMER may, as its sole remedy, terminate this Agreement
without any further liability to SELLER. Nothing contained herein shall obligate
the CUSTOMER to pay for any Products that do not conform to any purchase order
or release or any Software that does not meet the applicable specifications in
any materially adverse respect.

        10.5 In addition to the right of CUSTOMER to terminate this Agreement as
set forth in this Section 10, the Parties shall have the following rights: If at
any time competent public authority shall revoke or suspend CUSTOMER's Federal
Communications Commission (FCC) permit to construct or operate its network, or
if CUSTOMER without fault on its part shall be denied access reasonably
requested to the incumbent local exchange carrier's ("ILEC") central office due
to the Product not meeting the ILEC's standards, CUSTOMER may issue a written
notice to SELLER to "STOP WORK". In such event all work in progress shall be
halted and any executory items on the schedules in the Attachments hereto shall
be automatically canceled. At such time as the impediment is removed, the
Parties shall in good faith negotiate new schedules considering commitments
SELLER has made in the interim, and SELLER shall be entitled to an equitable
adjustment in the price to be paid under this Agreement for any increased costs
to SELLER associated with the Stop Work notice. If such impediment is not
removed within six (6) months, then CUSTOMER may issue notice to SELLER of
termination of this Agreement, together with any documentation evidencing the
circumstances, and be released from any remaining minimum commitment hereunder.
The CUSTOMER hereby represents and warrants to the SELLER as of the date of this
Agreement that, to the best of its knowledge, no circumstances exist that would
permit CUSTOMER to exercise its rights under this Section 10.5.

        11. PUBLICITY. The Parties shall announce this Agreement and the
establishment of the relationship between CUSTOMER and SELLER under this
Agreement pursuant to a joint press release to be mutually agreed upon. The
Parties agree to submit to each other for approval all other press releases
relating to this Agreement and to not publish any press release without prior
approval of the other Party, which approval shall not be unreasonably withheld
or delayed.

        12. ASSIGNMENT. This Agreement shall be binding on successors and
assigns, provided, however, this Agreement may not be assigned or transferred by
one Party without the prior written consent of the other Party, which consent
shall not be unreasonably withheld or delayed. Notwithstanding the foregoing
sentence, an assignment by operation of law to a company under common ownership
and/or control with the assigning Party, or to an acquirer of all or
substantially all of the assigning Party's stock, assets or business to which
this Agreement pertains, shall not require the consent of the other Party, but
rather, in such cases, the assigning Party shall give written notification of
such assignment to the other Party. Any purported assignment in violation of
this Section 12 shall be null and void.



                                                                              9.
<PAGE>   11

        13. MISCELLANEOUS.

        13.1 No Waiver. A waiver by either Party of any provision of this
Agreement or breach, in any one instance, shall not be construed as a waiver of
any other provision or subsequent breach thereof.

        13.2 Notices. All notices or communications of any kind made or required
to be given pursuant to this Agreement shall be in writing and delivered by
facsimile, if to SELLER, to Mr. Suresh Nihalani, Accelerated Networks, Inc.,
fax: (805) 553-9690, tel: (805) 553-9860, and if to CUSTOMER, to Mr. Frederic
Kunzi, CTC Communications Corp., fax: (781) 890-1613, tel: (781) 466-1391, or by
hand delivery or by nationally recognized overnight mail service, or sent by
first class mail, postage prepaid to the address for such Party specified in
this first paragraph of this Agreement or such other address or number as such
Party shall provide notice of in accordance with this Section 13.2.

        13.3 Governing Law. The validity, interpretation and effect of this
Agreement shall be governed by the law of the State of California, without
regard to conflicts of law provisions thereof.

        13.4 Severability. If any provision of this Agreement is held by a court
of competent jurisdiction to be illegal, invalid or unenforceable, that
provision shall be limited or eliminated to the minimum extent necessary so that
this Agreement shall otherwise remain in full force and effect and enforceable.

        13.5 Force Majeure. A Party shall not be liable for non-performance or
delay in performance (other than of confidentiality obligations) caused by any
event reasonably beyond the control of such Party including, but not limited to
wars, hostilities, revolutions, riots, civil commotion, national emergency,
strikes, lockouts or other labor disputes or shortages or inability to obtain
material or equipment, unavailability of supplies, compliance with laws or
regulation (including, without limitation, those related to infringement),
epidemics, fire, flood, earthquake, force of nature, explosion, embargo, or any
Act of God, or any law, proclamation, regulation, ordinance or other act or
order of any court, government or governmental agency.

        13.6 Entire Agreement; Amendment. This Agreement, including all
Attachments to this Agreement, constitutes the entire agreement between the
Parties relating to the subject matter hereof and all prior or simultaneous
proposals, negotiations, representations, conversations, discussions and
agreements, whether written or oral, among the Parties and all past dealing or
industry custom. This Agreement may not be amended except by a writing signed by
the Parties, or by a purchase order as described in Section 1.1.

        13.7 Counterparts. This Agreement may be executed in two or more
counterparts, ach of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.



                                                                             10.
<PAGE>   12

        IN WITNESS WHEREOF, the Parties hereto have executed this Product
Procurement Agreement (PPA) for Strategic Account effective as of the day and
year first above written.



"SELLER":                                    "CUSTOMER":


ACCELERATED NETWORKS, INC.                   CTC COMMUNICATIONS CORP.



By:     /s/ Suresh Nihalani                  By:   /s/ Frederic Kunzi
        ----------------------------               -------------------------
        Suresh Nihalani                      Name:    Frederic Kunzi
        President & CEO                      Title:   CTO



                                                                             11.