<PAGE>

EXHIBIT 10.1 ORIGINAL EQUIPMENT MANUFACTURER/PRIVATE LABEL AGREEMENT

                            CONFIDENTIAL TREATMENT

                       Original Equipment Manufacturer/
                            Private Label Agreement


This Agreement is made this 4/th/ day of January, 2001 by and between G3M
Corporation, with its principal place of business at 4320 Stevens Creek Blvd,
San Jose, CA 95129, (hereinafter "SELLER") and Larscom Incorporated, with its
principal place of business at 1845 McCandless Drive, Milpitas, CA 95035,
(hereinafter "BUYER"). This Agreement sets forth the terms and conditions for
the sale of Products by SELLER, and the purchase of the same by BUYER.

1.       DEFINITIONS

         1.1      "SELLER's Products" shall mean all SELLERS hardware products
                  set forth in Exhibit "A" hereto, including all firmware
                  incorporated as part of the hardware, and all necessary
                  Documentation relating thereto.

         1.2      "SELLER's Software" shall mean all software incorporated in
                  SELLER's Products which includes all software listed in
                  Exhibit "A", all software upgrades, and all necessary
                  Documentation relating thereto.

         1.3      "Documentation" consists of all manuals, release notices, and
                  other materials generally made available to the customers of
                  SELLER with the sale of SELLER's Products and/or Software.

2.       EFFECTIVE DATE OF AGREEMENT AND TERM

         This Agreement shall become effective as of the date set forth above
         and shall continue in full force and effect for ***** from such date.
         At the end of the initial ***** term, BUYER shall have the right to
         renew this Agreement, upon the same terms and conditions provided
         herein, for additional ***** terms. In the event BUYER does not wish to
         exercise its rights under the preceding sentence, BUYER shall provide
         written notice to SELLER not later than ***** prior to the end of the
         initial and/or subsequent term(s) of this Agreement.

3.       PRICING AND DISCOUNTS

         3.1      Pricing - The List Prices for the Products are set forth in
                  -------
                  Exhibit "A" and shall not be increased during the *****
                  period. The List Prices may be increased by SELLER once at
                  each ***** period provided that the List Price has changed for
                  all customers and that SELLER provides BUYER with a *****
                  prior written notice of such proposed price increase. In the
                  event that BUYER does not accept the increased prices, or that
                  discounts offered are unacceptable to BUYER, BUYER shall have
                  the right to terminate this Agreement, and/or any underlying
                  purchase orders, without penalty.

         3.2      Discounts - SELLER shall sell to BUYER the Products at the
                  ---------
                  List Prices less the applicable discounts specified in Exhibit
                  "B" as ordered by BUYER on BUYER's purchase orders pursuant to
                  this Agreement.


Confidential treatment has been requested for portions of this exhibit. The copy
herewith omits the information subject to the confidentially request. Omissions
are designated as *****. A complete version of this exhibit has been filed
separately with the Securities and Exchange Commission.

                                      21
<PAGE>

                            CONFIDENTIAL TREATMENT

         3.3      ***** Customer - SELLER represents that the ***** are ***** by
                  --------------
                  the SELLER to ***** in the ***** under similar terms and
                  conditions. Should SELLER ***** to any *****, SELLER shall, at
                  the same time, ***** for the ***** under *****. Such *****
                  shall apply to ***** shipped within thirty (30) days prior to
                  the *****, and to ***** but not yet shipped, and to *****
                  thereafter purchased pursuant to this Agreement.

         3.4      Taxes - Prices set forth in this Agreement are exclusive of
                  -----
                  any and all Federal, state and local excise, sales, use or
                  similar taxes. When applicable, such items shall appear as
                  separate additional items on SELLER's invoices and shall be
                  paid by BUYER.

4.       TERRITORY

         This agreement provides for BUYER to sell Products on a ***** basis
         except for those countries listed in Exhibit E.

5.       SPARE PARTS

         5.1      Availability - SELLER shall maintain a supply of spares to
                  ------------
                  perform warranty and out-of-warranty repairs to Products, or
                  make such spares available for sale to BUYER as described
                  below, for a period of seven (7) years after the delivery of
                  the last unit of Product to BUYER under this Agreement, or
                  discontinuation of such Product, whichever is later.

         5.2      Purchase - BUYER may, at any time, opt to purchase spare parts
                  --------
                  to directly support its installed customer base. SELLER agrees
                  to make available to BUYER the spare parts as may be mutually
                  agreed upon for specific items and prices. Emergency orders
                  for spare parts placed as a result of a machine down condition
                  shall be shipped within one business day, after receipt of
                  BUYER's purchase order number, (transmitted by facsimile or
                  e-mail), by SELLER. Routine orders for spare parts shall be
                  shipped within thirty (30) days after receipt of BUYER's
                  purchase order number by SELLER. In the event that SELLER
                  cannot comply with the agreed to delivery schedules set forth
                  above, Seller agrees to provide completed units of Product
                  (versus individual spare parts) for use by BUYER for
                  replacement of its customers' equipment, within the same
                  time-frames.

6.       TERMS OF PAYMENT

         Invoices shall be rendered by SELLER no earlier than the date of
         shipment of Products or completion of services rendered hereunder.
         Payment shall be made on undisputed invoices, in full, net thirty (30)
         days after receipt of invoice; provided however, that BUYER need not
         pay for unsatisfactory Products rejected under this Agreement and
         returned. Payment shall not constitute acceptance of any Products by
         BUYER.

7.       ORDERING

         7.1      Purchase Orders - SELLER agrees to be prepared to ship the
                  ---------------
                  Products listed in Exhibit "A". BUYER shall provide SELLER
                  with purchase orders from time to time directed to the
                  attention of Order Administration at SELLER's Principal
                  location, and SELLER agrees to deliver said Products. Said
                  purchase orders shall refer to and indicate that they are
                  being submitted subject to the terms and conditions of this
                  OEM Agreement between BUYER and SELLER. All purchase orders
                  submitted under this Agreement shall be governed and
                  controlled by the conditions of this Agreement, which shall
                  take precedence over any conflicting terms and conditions
                  contained in any purchase order or acknowledgement. Purchase
                  orders submitted under this Agreement will specify:


***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      22
<PAGE>

                            CONFIDENTIAL TREATMENT

                  a)       identity of the Products ordered;
                  b)       the quantity of each such Product ordered;
                  c)       the discounted unit price for each such Product;
                  d)       shipping instructions;
                  e)       date of delivery at BUYER's or BUYER's Customer
                           dock; and
                  f)       any other special  information  required by this
                           Agreement or by the  circumstances  of the order.

         7.2      Product Forecasts - At the request of the SELLER, BUYER will
                  -----------------
                  provide monthly forecasts of Products which BUYER estimates it
                  will need, for at least the subsequent six (6) month period;
                  however, in no event shall BUYER be obligated to purchase the
                  amounts of Products set forth in the forecast.

         7.3      Quotas - There are no minimum quotas or quantities which BUYER
                  ------
                  is required to purchase under this Agreement.

8.       DELIVERY

         8.1      Delivery/Shipping - All deliveries will be made F.O.B.
                  -----------------
                  SELLER's factory at 4320 Stevens Creek Blvd, # 275, San Jose,
                  CA 95129. SELLER agrees to drop-ship Products directly to
                  BUYER's Customers in accordance with BUYER's instructions.
                  Products shall be packed in accordance with SELLER's best
                  standard commercial practices as approved by BUYER or in
                  accordance with BUYER's instructions, if any are given, so as
                  to prevent damage during shipment.

         8.2      Title, Risk of Loss, Freight Charges - Title and risk of loss
                  ------------------------------------
                  shall, subject to proper packing and proper delivery of the
                  subject Products to the carrier, pass to BUYER upon delivery
                  to the common carrier or BUYER's representative at the F.O.B.
                  point. All transportation charges shall be freight collect
                  unless otherwise specified. BUYER will notify SELLER relative
                  to any shipment shortage within thirty (30) days from BUYER's
                  receipt of the shipment.

         8.3      Rescheduling - BUYER shall be entitled to, at any time between
                  ------------
                  31 and 90 days prior to the scheduled shipment date,
                  reschedule and postpone up to ninety (90) days, Products
                  having up to 50% of the dollar value of the Products scheduled
                  for shipment. Buyer shall also be entitled to, at any time
                  prior to 90 days before any scheduled shipment date,
                  reschedule and postpone up to 90 days, the delivery of any
                  products scheduled for shipment.

         8.4      Lead Times - Purchase orders shall specify a mutually agreed
                  ----------
                  to delivery lead time not to exceed thirty (30) days after
                  receipt of BUYER's verbal purchase order. Reduced lead times
                  may be requested by BUYER ("Expedited Orders") for reasonable
                  quantities of Products. SELLER agrees to provide BUYER with
                  timely notice of any delay in Product production or delivery.
                  BUYER's knowledge of such delays is not a waiver, direct or
                  implied, of SELLER's production or delivery obligations
                  hereunder.

         8.5      Safety Stock - SELLER agrees to maintain a safety stock equal
                  ------------
                  to five percent (5%) of the total previously shipped units up
                  to a maximum of twenty-five (25) units, but no less than five
                  (5) units, in order to promptly support Expedited Orders and
                  handle unforeseen BUYER requirements.

         8.6      Late Deliveries - In the event SELLER does not ship Products
                  ---------------
                  within the agreed to time frame as shown on BUYER's purchase
                  order(s), and if the shipment is more than five (5) days late,
                  BUYER will advise Seller of requirements imposed by its
                  customer. BUYER and SELLER will then use their best efforts to
                  meet customer requirements and if these are not met in the
                  next 30 days, then BUYER may cancel the order(s) without
                  penalty.

                                      23
<PAGE>

                            CONFIDENTIAL TREATMENT

9.       CHANGES

         BUYER may at any time request SELLER to make changes within the general
         scope of this Agreement in any of the following: (i) the Specification;
         (ii) SELLER's method of shipment or packing; (iii) the quantities of
         Products to be delivered hereunder; (iv) the place of delivery; and/or
         (v) the delivery schedule. If any such change causes an increase in the
         cost of, or time required for, performance under this Agreement, SELLER
         shall have ninety (90) days to submit a proposal detailing the
         adjustments in the price and/or delivery schedule for Products directly
         affected by requested BUYER's changes.

10.      TESTING AND INSPECTION, ACCEPTANCE

         Payment for the Products delivered hereunder shall not constitute
         acceptance thereof. The BUYER may elect at anytime, and from time to
         time, to source inspect any and all of the Products for the BUYER in
         the SELLER's facility before shipment to the BUYER or BUYER's
         customers. The BUYER may, at its option, elect to either source inspect
         the Product, or waive source inspection in favor of in-house inspection
         for that shipment. BUYER shall have the right to reject any or all of
         said Products within thirty (30) days after BUYER'S receipt of the
         Products, which are, in BUYER's reasonable judgment defective or
         nonconforming. Products rejected and Products supplied in excess of
         quantities called for in BUYER's purchase order may be returned to
         SELLER at its expense. In the event BUYER or BUYER's customer receives
         Products whose defect or nonconformity are not apparent on inspection,
         BUYER reserves the right to require replacement. Nothing contained in
         this Agreement shall relieve in any way SELLER from the obligation of
         testing, inspection and quality control.

11.      QUALITY ASSURANCE

         SELLER agrees to maintain a formal Quality Assurance Program which may
         be reviewed by BUYER for approval. On a periodic basis and/or upon
         determination of need based upon problems, SELLER shall be subject to a
         quality audit. These audits to be performed by BUYER's Quality
         Representative, shall serve to verify that SELLER is maintaining or
         improving quality and operational capabilities.

12.      AGENCY APPROVALS

         SELLER agrees that all Products sold hereunder shall meet UL and CSA
         specifications and have been recognized and labeled accordingly. SELLER
         shall provide BUYER with a copy of the UL and CSA
         recognition/certification. SELLER agrees that all Products sold
         hereunder shall meet the FCC Part 15, Subpart J regulations for Class A
         computer devices and FCC Part 68, and any other applicable FCC
         regulations, and shall be labeled accordingly. SELLER shall provide
         BUYER with a copy of the FCC recognition/certifications.

13.      WARRANTY

         13.1     Warranty Coverage - SELLER warrants that the Products and/or
                  -----------------
                  Software sold hereunder will conform to the applicable
                  specifications (attached hereto as Exhibit "D") and will be
                  free from defects in material and workmanship for a period of
                  twenty four (24) months from the date of receipt of Product
                  and/or Software at BUYER's facility or twenty four (24) months
                  from the date of receipt of Product and/or Software at BUYER's
                  customer facility if product is drop-shipped by SELLER.

         13.2     Repair/Replacement - If any Products are defective in
                  ------------------
                  materials or workmanship, or do not conform to specifications,
                  BUYER or BUYER's customers shall have the right to return them
                  to SELLER. The defective Products will be returned, with a
                  description of the failure, freight prepaid. The defective
                  Products will either be repaired or replaced at SELLER's
                  option and at no charge to BUYER or BUYER's customer, within
                  ten (10) working days of receipt, and returned freight prepaid
                  to BUYER or BUYER's customer as directed by BUYER. SELLER
                  shall notify BUYER if the Product will be replaced. In the
                  event that the same unit of Product
                             CONFIDENTIAL TREATMENT

                                      24
<PAGE>

                  is sent to SELLER for repair more than once due to the same
                  mode of failure, then SELLER must replace the unit or
                  defective components with new Product.

         13.3     Dead On Arrival - If a product arrives "Dead on Arrival"
                  ---------------
                  (DOA), SELLER will, within twenty-four (24) hours from
                  notification, ship a replacement unit to BUYER or BUYER's
                  customer freight pre-paid. BUYER agrees to return DOA product
                  to SELLER within 15 days, freight collect.

         13.4     Breach of Warranty - Should SELLER, for any reason, fail to
                  ------------------
                  honor the warranty provisions herein, SELLER shall be deemed
                  in breach of this Agreement. BUYER may pursue any and all
                  other remedies available as discussed in paragraph 46. Dispute
                  Resolution. SELLER acknowledges that BUYER has an independent
                  reputation with its customers which BUYER may desire to
                  protect despite any breach by SELLER.

         13.5     Out-of Warranty Repairs - SELLER shall provide out-of-warranty
                  -----------------------
                  repair and replacement services for all Products furnished
                  under this Agreement for a period of seven (7) years from date
                  of discontinuation of the Product, or the date of delivery of
                  the Product, whichever is later. Charges for such
                  out-of-warranty repairs shall be at SELLER'S then current
                  charges less any applicable discounts.

14.      *****

         14.1     Grant *****- BUYER acknowledges that the software and firmware
                  -----------
                  resident in the Products is confidential, proprietary and/or
                  copyrighted by SELLER. SELLER hereby grants to BUYER a *****
                  and *****, under all patents and proprietary interests owned
                  or controlled by SELLER and pertaining to the Products herein,
                  to use ***** the Products.

         14.2     Restrictions - The software and firmware provided hereunder,
                  ------------
                  including any subsequent improvements or updates, are
                  furnished to BUYER under a ***** and ***** for use in a *****.
                  BUYER agrees that all software and firmware shall not be sold
                  or distributed or otherwise made available to customers or
                  other third parties separate from the Product in which it is
                  resident, nor copied or tampered with, nor shall its removal
                  be attempted, except for copies made for archival purposes.
                  BUYER agrees that, in connection with the transfer of any
                  Product to its customer and in connection with any subsequent
                  transfer by its customer to a third party, it will
                  contractually restrict all such transferees such that they
                  shall:

                  a)       limit the use of the software and firmware thereof to
                           that Product transferred by BUYER, and

                  b)       not reverse assemble or reverse compile any of the
                           software or firmware.

15.      EPIDEMIC OF FAILURES

         Notwithstanding the warranty provisions of this Agreement, or any other
         provision of this Agreement, if an epidemic of failures of functional
         specifications or nonconformity's of the Products occur, due to the
         same specifically identified symptom, at rate greater than five percent
         (5%), within any two (2) month period, of a five (5) year span, from
         date of shipment by SELLER regardless of whether the Products are in or
         out of warranty, SELLER agrees to use its best efforts (at its expense)
         to remedy the failed Products and to prevent the problem from occurring
         in future deliveries


***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      25
<PAGE>

                            CONFIDENTIAL TREATMENT

         In the event that SELLER is unable to remedy the problem in the
         Products, BUYER may, at its option, cancel any and all purchase orders
         or portions thereof for Products which are experiencing the epidemic
         failures and BUYER may return, for full credit, the Products which are
         under warranty and are experiencing the epidemic failures and which
         have already been received by BUYER or BUYER's Customers. BUYER may at
         its option, elect to replace said Products with products which fulfill
         BUYER's customer's needs and invoice SELLER for all reasonable expenses
         incurred. Further, BUYER may cancel any and all purchase orders or
         portions thereof for Products which were used in, or in conjunction
         with, the Products experiencing the epidemic of failures (e.g., spare
         parts, accessories, etc.), and BUYER may return freight collect and for
         full credit, such Products which have already been received.

16.      EMERGENCY SUPPORT

         In the event of an emergency involving SELLER's Product at BUYER's
         facilities or BUYER's customer's site, SELLER will provide to BUYER
         qualified factory technical support when such assistance is required by
         BUYER within twenty-four (24) hours, not to exceed forty-eight (48)
         hours, upon notice given by the Manager or Director of Customer Service
         Operations, or other persons designated by BUYER. SELLER shall
         designate one or more contact persons who will be responsible for
         assuring that the emergency support is provided. Whether the cost of
         the emergency assistance shall be borne by SELLER or BUYER depends on
         whether the Products are under warranty and in compliance with SELLER's
         specifications. If the Product is in compliance with the
         specifications, or if the product is not under warranty, BUYER will
         bear the cost and will be billed (except in situations involving
         epidemic failures as described in Section 15, above) at SELLER's then
         prevailing published rates. If the Product is under warranty or not in
         compliance with SELLER's specifications, then SELLER shall bear the
         cost of the emergency assistance.

17.      TECHNICAL SUPPORT AND DOCUMENTATION

         17.1     Technical Support - SELLER will provide the following support
                  -----------------
                  at BUYER's plant or BUYER's customer site:

                  a)       Engineering Support, *****, to BUYER's Engineering
                           personnel in the form of telephone consultation by
                           SELLER's Engineering personnel during normal work
                           hours.
                  b)       Field Support, *****, to BUYER's Customer Service
                           Engineering personnel in the form of telephone,
                           facsimile or e-mail consultation by SELLER's support
                           organization and technical assistance specialists on
                           a 24 hour-a-day seven day-a-week basis.

                  c)       Emergency Support, *****, to BUYER's Customer Service
                           Engineering personnel, to include appropriate
                           escalation procedures, by SELLER'S support
                           organization and technical assistance specialists on
                           a 24 hour-a-day, seven day-a-week basis.

         17.2     Documentation - Concurrent with the date of this Agreement,
                  -------------
                  SELLER will provide BUYER with a list of all
                  documentation/manuals available or planned for general
                  information, training and for maintenance of the Products.
                  Such documentation may include, but not be limited to,
                  maintenance manuals (which typically include site preparation,
                  installation, operation, functional description, preventative
                  maintenance, maintenance procedures, logic block diagrams for
                  the Products), logic card manuals which include card layout,
                  technical memos or bulletin file, and copies of documentation
                  covering any Product changes (as described in


***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      26
<PAGE>

                            CONFIDENTIAL TREATMENT

                  paragraph 23, herein). SELLER hereby grants, at no charge to
                  BUYER, the right to reproduce, translate into other languages,
                  and prepare derivative works, distribute, sell, perform and
                  display, in whole or in part, manuals and documentation
                  specified herein. During the term of this Agreement, SELLER
                  shall provide BUYER with written notification sixty (60) days
                  or more prior to the general release of said documentation.
                  BUYER may integrate such changes into its version of the
                  documentation at BUYER's option.

18.      TRAINING

         SELLER agrees to provide ***** training courses per year to BUYER
         *****. Additional training courses shall be provided at a cost to be
         mutually agreed upon. For training courses taught at locations other
         than SELLER's facilities, BUYER agrees to reimburse SELLER for
         reasonable travel and living expenses of the instructor.

19.      ESCROW

         At BUYER's request and expense and at any time during the term of this
         Agreement, SELLER will be prepared to place in escrow all documentation
         necessary for the production and manufacture of Products covered under
         this Agreement, such as, but not limited to, engineering, manufacturing
         and software source code documentation ("Escrow Material"). The
         designated escrow agent will be instructed to deliver to BUYER said
         documentation and source code in the event of an arbitration event
         relating to a default by SELLER as outlined in Article 30 herein, so
         that BUYER may manufacture and support the Products and/or Software.
         All intellectual properties remain as property of SELLER.

20.      CONFIDENTIAL INFORMATION

         Any knowledge or information which either party has disclosed or may
         hereafter disclose to the other, which is marked with a confidential or
         proprietary notice in connection with the purchases hereunder, shall
         not be disclosed, revealed, or transmitted to anyone by the other party
         nor shall either party permit such to be disclosed, revealed, or
         transmitted to any third party. This provision shall survive the
         expiration or termination of this Agreement.

         With the exception of software and firmware resident in the Products,
         SELLER agrees that it will not disclose to BUYER any information which
         it deems as confidential or proprietary unless BUYER agrees in advance
         to such disclosure and it is done pursuant to a separate Confidential
         Disclosure Agreement entered into by BUYER and SELLER which is part of
         this Agreement by an Addendum hereto as Exhibit D.
21.      PATENT AND SIMILAR INDEMNITY

         Except as hereinafter limited, SELLER shall defend at its own expense
         and indemnify BUYER from and against any liability (including
         attorneys' fees and costs) arising out of any claim that any Product
         and/or Software purchased hereunder infringes a valid patent or is a
         violation of copyright, trade secret, or other proprietary rights of
         third parties, provided that, BUYER shall promptly give SELLER timely
         written notice thereof and reasonable cooperation, information and
         assistance in connection therewith, and SELLER shall have sole control
         and authority with respect to defense, settlement, or compromise
         thereof. Should Products delivered hereunder become or, in SELLER's
         opinion, be likely to become the subject of such a claim, SELLER may at
         its option, either procure for BUYER the right to continue using such
         Products, or replace or modify the Products so that they become
         non-infringing.



***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      27
<PAGE>

                            CONFIDENTIAL TREATMENT

22.      INDEMNIFICATION

         SELLER shall defend, indemnify, and hold BUYER harmless from property
         damage, personal injury or expense, including attorneys fees and costs,
         incurred by any employee, agent, invitee or ***** of BUYER, or any
         other person, regardless of how caused if arising out of the use or
         possession of the Products and/or Software by BUYER or BUYER's
         customers unless such loss, property damage, personal injury, or
         expense, including attorneys fees, was caused solely by the gross
         negligence or willful misconduct of BUYER, its employees, its
         authorized agents or its customers.

23.      PRODUCT CHANGES; DISCONTINUANCE

         23.1     Product Changes - SELLER shall have certain rights, except as
                  ---------------
                  stated herein, to make changes to the Products. A "material
                  change" is defined as one which affects the Products'
                  specified performance, maintainability, operation, safety,
                  reliability, backward compatibility, interface, form, fit, or
                  function. A "minor change" is a change which would not be a
                  "material change". SELLER shall have full freedom to make
                  minor changes so long as such changes are not deemed to be
                  material changes.

                  Prior to instituting any change, whether minor or material,
                  SELLER will provide BUYER with six (6) months advance notice
                  of the proposed change. The notice shall include SELLER's
                  change control forms for both hardware, software and firmware.
                  In said notice, SELLER shall state whether it deems such
                  proposed change to be minor or material. As to "material
                  changes", SELLER shall work with BUYER to discuss the impact
                  of such change and shall assist BUYER in minimizing the impact
                  of such changes upon BUYER's customers. If it is determined
                  that sample parts or Products are required to assess such
                  impact, SELLER will provide at least two (2) sets of such
                  parts or Products at no charge for evaluation. BUYER will
                  either approve or reject, with just cause, all material
                  changes within thirty (30) business days after receipt of
                  written notification and/or required sample parts or Products
                  from SELLER. If change for Product reliability is needed on an
                  emergency basis, the change will be immediately sent to BUYER
                  who will make best efforts to respond within seventy-two (72)
                  hours.

                  The SELLER will supply BUYER with upgrade kits to incorporate
                  all field mandatory changes and retrofit all Products
                  delivered to BUYER's customers prior to the change at no
                  charge. Such upgrade kits may include hardware and/or
                  software.

                  In the event that BUYER rejects a material change, then BUYER
                  may either,

                  a)       terminate  any and all purchase  orders or portions
                           thereof for  Products  and/or spare parts affected
                           by the change without cost or penalty, or

                  b)       request SELLER to continue manufacture and support
                           the Products which are the subject of the proposed
                           change, as it is then being manufactured, for so long
                           as BUYER requires said Product and with no increase
                           in the purchase price except as provided by 3.1

         23.2     Discontinuance - SELLER agrees to notify BUYER in writing not
                  --------------
                  less than six (6) months in advance of the discontinuance of
                  any Product. SELLER agrees to support such discontinued
                  Products for a period of seven (7)


***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                             CONFIDENTIAL TREATMENT

                                      28
<PAGE>

         23.3     years from the date of notice of such discontinuance. For the
                  purposes of this paragraph "support" shall mean supplying
                  hardware, repair and replacement services, software systems,
                  and supplying associated documentation,

         23.4     and all that is required to maintain the Products. The support
                  shall be furnished at SELLER's then current prices, less the
                  same discount, which BUYER was receiving prior to the
                  discontinuance.

24.      PRODUCT ENHANCEMENT, UPGRADES AND NEW PRODUCTS

         SELLER shall provide BUYER with non-confidential information regarding
         future enhancements and upgrades to be made to the Products, as well as
         information regarding releases of new Products. These enhancements,
         upgrades, and new Products will, at BUYER's option and under mutually
         agreed terms, be included in this Agreement as "Products", when
         released. As soon as reasonably possible after each phase of testing of
         enhancements, upgrades, or new Products, SELLER agrees to make such
         enhancements, upgrades, or new Products and/or information regarding
         the testing performed with such, available to BUYER for analysis and
         review; the purpose of this provision is to allow BUYER to be aware of,
         and familiar with, Product enhancements, upgrades, and new Products
         prior to their release. SELLER agrees that prices for the upgrades,
         enhancements, and new Products will be consistent with SELLER's OEM
         pricing policies in this Agreement.

25.      REPAIRS

         25.1     Repairs - SELLER shall establish a repair service for Products
                  -------
                  in or out-of-warranty. SELLER will have the option to repair
                  or replace components of the returned Product. SELLER shall
                  ensure that the replacement or repair turnaround will not
                  exceed ten (10) working days from the time the Product is
                  received at SELLER's repair facility. Furthermore, in the
                  event that SELLER is consistently late in repairing or
                  replacing Products, SELLER shall be deemed in breach of this
                  Agreement, and in such event, BUYER shall give SELLER notice
                  and a thirty (30) day period of time in which to cure such
                  breach. SELLER agrees to notify BUYER immediately of any
                  replacement or repair which is likely to exceed the ten (10)
                  day turn-around time.

                  SELLER agrees to provide BUYER with a monthly report of all
                  repair and/or replacement activities on SELLER's products
                  received from BUYER or BUYER's customer for servicing.

                  SELLER agrees to make all necessary repairs to parts and/or
                  components of Products at the mandatory revision level or
                  equivalent for a period of seven (7) years after the last
                  delivery of such Products under this agreement or seven (7)
                  years from the date of discontinuance of any Products from the
                  product line of SELLER, whichever is later. SELLER agrees to
                  supply spare parts during the periods described above for
                  delivery within thirty (30) days of placement of the order by
                  BUYER; prices for such spare parts shall be at SELLER's then
                  current prices less the same discounts which BUYER was
                  receiving prior to the end of this Agreement.

                  In the event of unavailability of any spare part or suitable
                  substitute which is interchangeable and backward compatible,
                  SELLER shall make available to BUYER, SELLER's manufacturing
                  drawings and specifications for the parts, tools or test
                  equipment which are unavailable for purchase from SELLER or
                  its vendor. In addition, SELLER shall also grant to BUYER
                  and/or BUYER'S vendors, such manufacturing rights as SELLER
                  may have and be able to convey to be used by BUYER or BUYER's
                  vendors at no additional charge. Prior to the discontinuance
                  of production, BUYER and SELLER will work together to
                  establish a plan to support BUYER's installed base.

                                      29
<PAGE>

                            CONFIDENTIAL TREATMENT

     25.2    Emergency Repairs - During the warranty period, SELLER agrees to
             -----------------
             provide a twenty-four (24) hour turn around time for emergency out
             of service conditions, at no additional cost to BUYER or BUYER'S
             Customer.

             For out-of-warranty emergency service, SELLER agrees to
             provide expedited repair services at a mutually agreed cost.

26.  PRIVATE LABELING/DOCUMENTATION

     26.1    Private Labeling - The parties agree that Product may be
             ----------------
             distributed under BUYER's private label. SELLER agrees to fill all
             orders under this Agreement with unique "Larscom" labeling as
             requested by BUYER, unless otherwise specified on the order.
             Products designated with Larscom labeling shall only be supplied by
             SELLER to BUYER or such third parties as BUYER may specifically
             designate in writing.

             SELLER agrees to affix any labels, numbering, or symbols to the
             products, packaging, software, and documentation accompanying the
             Products, as reasonably requested by BUYER. BUYER will provide the
             art work and instructions as required by SELLER's manufacturer.
             BUYER shall have the opportunity to approve the first faceplate
             with affixed labeling.. BUYER agrees to pay SELLER upon the signing
             of this Agreement, a one time private labeling charge of _____ for
             each faceplate labeled. BUYER's purchase orders must specify that
             products be so labeled.

     26.2    Documentation - BUYER may edit or create documentation (i.e.,
             -------------
             manuals, data sheets, product brochures) by substituting the
             "Larscom" name for that of SELLER, and may make any other changes
             as necessary to indicate private labeling. SELLER will provide the
             documentation to BUYER in suitable form for the editing as the
             parties may reasonably agree. BUYER will supply SELLER with
             sufficient quantities of such manuals to accommodate drop-ship
             requirements. SELLER shall enclose one (1) set of manuals with each
             system drop-shipped to BUYER's Customers.

27.  CUSTOM FEATURES/FUNCTIONALITY

     BUYER may request that SELLER develop additional features and/or functions
     that will be unique to the private labeled products purchased by BUYER
     under this Agreement where such features are not contemplated by SELLER for
     inclusion in its standard product range. SELLER agrees that such custom
     features and/or functionality will be available for distribution by BUYER
     on an exclusive basis, and that said custom features and/or functionality
     will not be integrated into SELLER's standard products, or the products
     which SELLER sells, distributes, private labels or furnishes to any of its
     other Customers. SELLER agrees that all interest, right and title in and to
     such custom features and/or functionality shall remain in BUYER. Design
     specifications, cost and development schedules for such custom
     features/functionality will be negotiated by the parties on a case-by-case
     basis.

28.  COMPETITIVE RESTRICTION

     SELLER agrees that, during the term of this Agreement and any extensions
     thereof, it will not enter into any other Reseller or OEM agreement,
     directly or indirectly, with any of BUYER's competitors, specifically: ADC,
     Verilink, Quick Eagle, or Adtran.

29.  PACKAGING

     SELLER agrees to package all orders in plain boxes with clear tape, or as
     otherwise reasonably instructed by BUYER. This will be done at no
     additional cost.

                                      30
<PAGE>

                            CONFIDENTIAL TREATMENT

30.  TERMINATION OF AGREEMENT

     30.1    This Agreement may be terminated by either party, at anytime during
             the initial and any renewal term hereof, upon the occurrence of
             certain events of default by the other party. The following events
             shall constitute an event of default by a party:

             (a)    if either party hereto applies for or consents to the
                    appointment of a receiver, trustee or liquidator of itself
                    or any of its property;

             (b)    if either party hereto makes a general assignment for the
                    benefit of creditors;

             (c)    if either party hereto is adjudicated as bankrupt or
                    insolvent;

             (d)    if either party hereto files a voluntary petition in
                    bankruptcy or a petition or answer seeking reorganization or
                    an arrangement with the creditors or seeks to take advantage
                    of any insolvency law or in an answer admits the material
                    allegations of a petition filed against it in any
                    bankruptcy, reorganization or insolvency proceeding, or an
                    order, judgment or decree is entered without the
                    application, approval or consent of the party, by any court
                    or governmental agency of competent jurisdiction, approving
                    a petition seeking reorganization of such party, or of all
                    or a substantial part of such party's assets, and such
                    order, judgment or decree continues unstayed and in effect
                    for any period of sixty (60) consecutive days;

             (e)    In the event of breach of any term or condition of this
                    Agreement, the non-defaulting party shall give written
                    notice to the defaulting party of the defaulting conditions
                    and of its intention to terminate the Agreement at some
                    future date not earlier than ninety (90) days from the
                    mailing date of said notice. Unless such default is
                    corrected by the defaulting party, as evidenced by the
                    concurrence of the non-defaulting party, prior to said
                    future date, the termination shall be effective as of said
                    future date.

     30.2    BUYER or SELLER may elect to continue to make or receive shipments
             of SELLER Products and/or Software despite a default by the other
             party. Such election shall not constitute a waiver of the default
             by BUYER or SELLER for any such default.

31.  COOPERATION

     SELLER agrees that it will fully cooperate with BUYER by executing and
     preparing any and all documents necessary in order to allow BUYER to have
     the Products included in the GSA schedule or equivalent government
     schedules.

     Further, in the event that BUYER becomes aware of and desires to
     participate in a project which is out of the ordinary course of business
     hereunder or one that has requirements which differ from usual application
     of SELLER's Products, then SELLER agrees to, in a timely manner, provide
     all reasonable and necessary information and assistance to BUYER which
     would allow BUYER to adequately respond to the opportunity. Examples of
     such projects include Requests for Proposals (RFP) and Requests for
     Information (RFI) issued by Service Providers.

     Where any United states government contract of BUYER's requires the
     inclusion of certain provisions in subcontracts, BUYER and SELLER agree to
     consult and reasonably cooperate relative to same.

32.  TRADEMARKS, TRADE NAMES

     SELLER recognizes the right of BUYER to the name "Larscom", and other BUYER
     symbols, trademarks, trade names, logos and any variance thereof ("BUYER's
     Marks") and SELLER agrees not to use BUYER's Marks without the express
     written consent of BUYER. SELLER agrees not to raise or

                                      31
<PAGE>

                            CONFIDENTIAL TREATMENT

     cause to be raised any question concerning the validity of BUYER's Marks,
     and to notify BUYER promptly of any unauthorized use of BUYER's Marks by a
     third party.

     BUYER recognizes the right of G3M Corporation, to the name " Panthera", and
     other SELLER symbols, trademarks, trade names, logos and any variance
     thereof ("SELLER's Marks"). BUYER agrees not to use SELLER's marks without
     the express written consent of SELLER.

33.  FORCE MAJEURE

     The obligations of the parties hereunder shall be suspended by the
     occurrence of any unforeseeable event beyond the control of the parties
     which renders performance impossible or onerous, such as acts of God, or,
     riot, sabotage, fire, explosion, flood, casualty, inability to obtain
     suitable and sufficient labor or materials, or law or regulation
     restricting performance.

34.  PRESS RELEASES

     No press release or any other announcement will be made by either party
     regarding this Agreement unless both parties agree to its content in
     writing. SELLER will not, without the prior written consent of BUYER, in
     any public matter refer to the BUYER'S purchase and resale of SELLER's
     Products hereunder.

35   NO WAIVER OF CONDITIONS

     Failure of either party to insist upon strict performance of any of the
     terms and conditions hereunder, or the delay in exercising any of its
     remedies, shall not constitute a waiver of such terms and conditions nor a
     waiver of any default nor a waiver of any remedy.

36.  COMPLIANCE WITH LAWS

     SELLER shall comply with all applicable Federal, State and Local laws
     including, but not limited to, those which specifically represent that any
     product to be delivered hereunder will be produced and sold in compliance
     with the requirements of the Fair Labor Standards Act of 1938, the
     Occupational Safety & Health Act, Federal Communication Commissions Act and
     the Consumer Products Safety Act, and all regulations issued pursuant to
     such statutes, as amended and applicable.

37.  EXPORT AUTHORIZATION AND TERRITORY

     Unless otherwise agreed to by SELLER in writing, BUYER shall assume all
     responsibility of obtaining any required export authorizations necessary to
     export from the United States any Products purchased hereunder or technical
     data or documents to be supplied hereunder by SELLER. BUYER shall not re-
     export Products or technical data or documentation supplied by SELLER,
     directly or through others, or the product of such data, to the prescribed
     countries for which such prohibition exists pursuant to sections of the
     U.S. Export Administration Regulations unless properly authorized by the
     U.S. Government.

38.  RELATIONSHIP OF THE PARTIES

     The relationship of the parties under this Agreement shall be and shall at
     all times remain one of independent contractor only. Neither party is an
     employee, agent, or joint venture partner of the other party. Neither party
     shall have the authority to assume or create obligation on behalf of the
     other party with respect to the Products or otherwise, and shall not take
     any action which has the effect of creating the appearance of its having
     such authority.

39.  TERMS AND CONDITIONS OF SALE

     All purchase orders and acknowledgements for Products of SELLER shall be
     subject to the terms and conditions of this Agreement. No other conditions
     or modifications of terms and conditions of this

                                      32
<PAGE>

                            CONFIDENTIAL TREATMENT

     Agreement shall be effective unless specifically agreed to in writing by an
     authorized representative of both parties. Failure of either party to
     object to provisions contained in any purchase order, acknowledgement or
     other communication from the other party shall not be construed as a waiver
     of these terms nor an acceptance of any such provision.

40.  SEVERABILITY

     If any one or more of the provisions, or portions of provisions of this
     Agreement shall be deemed by any court of competent jurisdiction to be
     invalid, illegal or unenforceable in any respect, the validity, legality
     and enforceability of the remaining provisions, or portion of provisions
     contained herein, shall not in any way be affected or impaired thereby, so
     long as the Agreement still expresses the intent of the parties. If the
     intent of the parties cannot be preserved, this Agreement shall either be
     renegotiated or rendered null and void.

41.  NOTICES

     All notices from one party to the other shall be in writing and either
     personally delivered or sent via certified mail, postage prepaid and return
     receipt requested to:

     SELLER:  G3M Corporation
              4320 Stevens Creek Blvd #275
              San Jose, CA 95129

     BUYER:   Contracts Administration
              Larscom Incorporated
              1845 McCandless Drive
              Milpitas, CA 95035

     or to such persons or places as either party may designate from time to
     time by notice hereunder. Such notices shall be deemed effective upon
     personal delivery or deposit in the mails in accordance herewith.

42.  AWARENESS

     It is understood by SELLER that BUYER and its affiliates are designers,
     manufacturers and distributors and are now in the market selling
     telecommunications products. Further, it is understood that this Agreement
     is for the purpose of supplementing BUYER's current product line and that
     some time in the future BUYER may cease to purchase SELLER's Products and
     offer only BUYER and/or associated companies' products, and/or other
     company's products. SELLER understands that BUYER may in the future,
     design, manufacture, and sell products equivalent or similar to those on
     Exhibit "A" hereto. However, this agreement may not be considered a license
     or permit to copy SELLER's proprietary intellectual property, except as
     provided for by this agreement and in the normal course of business.

43.  LIMITATION OF LIABILITY

     NEITHER PARTY SHALL BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, OR
     CONSEQUENTIAL DAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS OR
     REVENUE, LOSS OF USE OF THE EQUIPMENT OR ANY ASSOCIATED EQUIPMENT, OR COST
     OF SUBSTITUTED FACILITIES, EQUIPMENT OR SERVICES WHICH ARISE OUT OF
     PERFORMANCE OR FAILURE TO PERFORM ANY OBLIGATION CONTAINED WITHIN THIS
     AGREEMENT, WHETHER THE CLAIM IS IN CONTRACT, TORT (INCLUDING NEGLIGENCE),
     STRICT LIABILITY OR OTHERWISE EXCEPT AS PROVIDED UNDER ARTICLE 21 OR 22 OF
     THIS AGREEMENT.

                                      33
<PAGE>

                            CONFIDENTIAL TREATMENT

44.  HEADINGS

     The section headings in this Agreement are for reference only and shall
     have no substantive effect.

45.  ASSIGNMENT

     Neither party shall delegate any duties nor assign any rights or claims
     under this Agreement, without prior written consent of the other party,
     such consent not to be unreasonably withheld; and any such attempted
     delegation or assignment without consent shall be of no effect.

46.  DISPUTE RESOLUTION

     Seller and Buyer will attempt to settle any claim or controversy through
     consultation and negotiation in good faith and a spirit of mutual
     cooperation. If those attempts fail, then the dispute will be mediated by a
     mutually-acceptable mediator to be chosen by Seller and Buyer within 45
     days after written notice by a party demanding mediation.

     In the event that any dispute or disagreement under this Agreement, cannot
     be resolved mutually between the parties, such dispute or disagreement
     shall be submitted to arbitration in San Francisco, California under the
     rules of the American Arbitration Association. Any award or decision made
     in such arbitration process shall be final, binding upon the parties and
     enforceable through application to any court of competent jurisdiction.
     Each party shall bear its own costs in connection with such proceeding,
     except that the prevailing party in any arbitration shall be reimbursed by
     the other party for any reasonable expenses, including legal fees. No
     arbitration award shall include punitive damages.

47.  GOVERNING LAW

     The laws of the State of California shall govern the construction and
     performance of this Agreement.

48.  ENTIRE AGREEMENT

     This Agreement, together with material incorporated herein by reference,
     sets forth the entire and only agreement between BUYER and SELLER
     concerning the subject matter hereof. No provisions of this Agreement can
     be modified except by a written amendment signed by both parties.

49.  AUTHORITY

     BUYER and SELLER each represent to the other that it has due and proper
     authority to make and perform all duties and obligations set forth and
     contemplated by this Agreement.

     This Agreement shall be construed as containing, as part of it, the
     following enclosures:

     Exhibit A       -    Products / List Prices
     Exhibit B       -    Discounts
     Exhibit C       -    Product Specifications
     Exhibit D       -    Confidentiality Agreement
     Exhibit E            Territory

                                      34
<PAGE>

                            CONFIDENTIAL TREATMENT

     IN WITNESS WHEREOF, the parties have executed this Agreement on the dates
set forth below their respective signatures.

ACCEPTED BY:


 G3M Corporation                  LARSCOM INCORPORATED

By: /s/ Gary Beeson               By: /s/ Robert Coakley

Name: Gary Beeson                 Name: Robert Coackley

Title: President                  Title: President & Chief Executive Officer

Date: 1/4/2001                    Date: 1/4/2001

                                      35
<PAGE>

                            CONFIDENTIAL TREATMENT



                                   EXHIBIT A

                            PRODUCTS / LIST PRICES


                  G3M Corporation Price List (FOB San Jose, CA)

<TABLE>
<S>                                   <C>                                           <C>
-----------------------------------------------------------------------------------------
                                           Panther Optical Matrix
                                      Basic OC-48 Chassis with PM 50-HR
                                         Power Module and Management                *****
                                                   Module.
-------------------------------------------------------------------------------------------
   Catalog                        PM 50-HR High Reliability Dual Feed Power         *****
    1291                       Supply. Up to two Power modules may be used for
                             applications that require full redundancy. Each PM
                            power module may be driven with 48VDC or standard AC
                                                  voltages

                             [A single unit is included with the basic Panthera]
-------------------------------------------------------------------------------------------
                            PM-48VDC Power Module. Provides filtering, switching,
   Catalog                  and SNMP monitoring for power management where -48VDC
    1292                       is provided. Can be used where the dual voltage      *****
                                           PM-50HR is not required
-------------------------------------------------------------------------------------------
                                              Management Module
                               Allows configuration and SNMP management of the
                           system. Allows automatic configuration of the Panthera
   Catalog                                        modules.
    1201                        Console(RS-232) and LAN (10Base-T) Interfaces       *****

                              [The Management Module is included with the basic
                                                  Panthera]
-------------------------------------------------------------------------------------------
                                                 DS3 Module
   Catalog
    1231                               Supports Voice and Packet data               *****
                                                 75 Ohm BNC
-------------------------------------------------------------------------------------------
</TABLE>

                                      36
<PAGE>

<TABLE>
<S>                                   <C>                                           <C>
-------------------------------------------------------------------------------------------
                                               Quad 100Base-TX
                                     Each module includes four separate
                                  100Base-TX Ethernet connections that are          *****
                                         mapped to the STS payloads
                                                   4 RJ-45
-------------------------------------------------------------------------------------------
                                           OC-3 mm Optical Module
   Catalog                                       Multi-Mode                         *****
    1211                                      Dual SC connector
-------------------------------------------------------------------------------------------
                                           OC-3 sm Optical Module
   Catalog                                       Single Mode                        *****
    1212                                      Dual SC connector
-------------------------------------------------------------------------------------------
                                           OC-12 mm Optical Module
   Catalog                                       Multi-Mode                         *****
    1213                                      Dual SC connector
-------------------------------------------------------------------------------------------
                                           OC-12 sm Optical Module
   Catalog                                       Single Mode                        *****
    1214                                      Dual SC connector
-------------------------------------------------------------------------------------------
   Catalog                                Quad T1 Interface Module                  *****
    1232                                           4 RJ-45
-------------------------------------------------------------------------------------------
</TABLE>

***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      37
<PAGE>

                            CONFIDENTIAL TREATMENT



                                   EXHIBIT B

                                   DISCOUNTS


BUYER has the right under the terms of this agreement to purchase the products
shown in Exhibit A, together with such other products as may be added to BUYER's
catalog and price list, at a discount of ***** from BUYER's list prices.

***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      38
<PAGE>

                            CONFIDENTIAL TREATMENT



                                   EXHIBIT C

                            PRODUCT SPECIFICATIONS

                                      39
<PAGE>

                            CONFIDENTIAL TREATMENT

                                   EXHIBIT D

                            CONFIDENTIALITY AGREEMENT

This Agreement is made and entered into effective this 1st day of September,
2000, (hereinafter "Effective date"), by and between Larscom Incorporated a
Delaware corporation, having its principal office at 1845 McCandless Drive,
Milpitas, CA 95035 and G3M Corporation, a California corporation, having its
principal office at 4320 Stevens Creek Blvd., San Jose, CA 95129.

Confidential Information in the form of trade secrets, plans, know-how,
corporate procedures and programs, specifications, software, prototypes, and/or
other business, technical, confidential and proprietary information may be
disclosed under this Agreement. A party to this Agreement who receives the
Confidential Information of another party to this Agreement agrees to not use or
disclose to others such Confidential Information subject to the terms and
conditions herein.

Permitted Use of Confidential Information: Until the period of the time that the
Confidential Information is held in confidence expires, a party who has received
Confidential Information of another party will use the information only as
permitted by the disclosing party.

Duty of Care: A recipient of Confidential Information shall protect its
confidentiality by using the same degree of care, but no less than reasonable
care, to prevent the unauthorized use, dissemination, or publication as the
recipient uses to protect its own confidential information of a like nature.
Accordingly, the recipient agrees not to reproduce, disclose to any third party,
or use for any purpose not authorized by the disclosing party, any Confidential
Information or materials which (a) are disclosed to the recipient as being
confidential, or (b) bearing the designation "PROPRIETARY AND CONFIDENTIAL
INFORMATION" or similar designation in writing.

Exceptions to the Duty of Confidentiality: This Agreement imposes no obligations
with respect to proprietary information which: a) was in recipient's possession
before receipt from the disclosure; b) is now or later becomes public knowledge
through no fault of the recipient; c) is known to the recipient prior to the
effective date of this Agreement as substantiated by documentation; d) is
rightfully received from a third party without any accompanying secrecy
obligation; e) is independently developed by the recipient; f) disclosing party
expressly gives receiving party written permission to disclose or otherwise use;
or g) is disclosed under operation of law.

No Additional Rights or Obligations: No party listed herein will acquire any
intellectual property rights of the other under the terms of this Agreement.
Neither party under this Agreement has an obligation to purchase any service or
item, nor does any party have the obligation or the right to make, use, or sell
products or processes incorporating Confidential Information disclosed under
this Agreement.

Term and Termination: Disclosure of Confidential Information under this
Agreement may take place for a period of two (2) years from the Effective Date.
The confidentiality obligations of the receiving party shall survive and
continue beyond the expiration of the Information disclosure period for three
(3) years from the date of disclosure.

General: No party intends that any partnership, joint venture, or agency be
created by this Agreement. No party will publicly announce or otherwise disclose
to parties not subject to this Agreement the existence of this Agreement, its
purpose, or any of its terms and condition. Any additional or modifications to
this Agreement must be made in writing and signed by the parties to be bound by
the additions or modifications. This Agreement is made under and will be
construed in accordance with the laws of the State of California, U.S.A. This
Agreement shall not be assigned by either party without the written consent of
the other.

                                      40
<PAGE>

                            CONFIDENTIAL TREATMENT

This Agreement is the entire agreement between the parties concerning the
Confidential Information and supersedes all prior oral and written agreements
between them. This Agreement inures to the benefit of and binds the parties and
their successors, assigns or other legal representatives. No waiver, alteration
or cancellation of any of the provisions of this Agreement shall be binding
unless made in writing and signed by the party to be bound.

The undersigned warrants that he or she has the authority to enter into this
Agreement on behalf of the person or entity identified above his or her
signature.

IN WITNESS HEREOF, the parties have executed this Agreement on the date first
written above.

Larscom Incorporated                        G3M Corporation


By:______________________________           By:______________________________

Print Name:______________________           Print Name:_______________________

Title:____________________________          Title:____________________________

                                      41
<PAGE>

                            CONFIDENTIAL TREATMENT

                                    EXHIBIT E

                                   TERRITORY

Countries not included in this ***** agreement are:


*****

***** Confidential treatment has been requested for the redacted portions. The
confidential redacted portions have been filed separately with the Securities
and Exchange Commission.

                                      42