<PAGE>

                                                                   EXHIBIT 10.12

                               November 24, 1999

James Griffin
V.P. Manufacturing
Ciena Corporation/Core Switching Division
10201 Bubb Road
Cupertino, CA  95014

          Re: Sublease Amendment

Dear Jim:

This Letter Agreement is entered into between Durect Corporation ("Sublessor")
and Ciena Corporation ("Sublessee") for the purpose of amending the Sublease
Agreement between Sublessor and Sublessee dated March 10, 1999 ("Sublease") to
include additional space as part of the Subleased Premises for a specified
duration during the Term of the Sublease.

Ciena and Durect hereby agree that effective as of November 29, 1999 until March
31, 2000:

          a.  The Subleased Premises as defined in Section 2 of the Sublease
shall include all of the space designated as Area W1 on Exhibit B of the
Sublease (a copy of which is attached hereto for convenience of reference) which
is deemed to contain 3,655 rentable square feet ("Additional Space").


     b. The Base Monthly Rent as defined in Section 4 A of the Sublease shall be
        $34,128.60.

     c. Sublessee's Pro Rata Share as defined in Section 4 B for the purposes of
        computing Additional Rent shall be forty-nine percent (49%).

     d. Sublessor and Sublessee acknowledge that Sublessee intends to provide
        heating and/or air conditioning to the Additional Space, whereas
        Sublessor will continue to use the space designated as Area W2 on
        Exhibit B of the Sublease for warehouse and storage use and will not be
        providing air conditioning or heating to such space.  Therefore, with
        respect to the allocation of Utilities in Section 8 A of the Sublease,
        Sublessee's share shall be fifty-nine percent (59%).

     e. This terms of this Letter Agreement shall terminate on March 31, 2000 in
        which event Sublessee shall surrender the Additional Space in accordance
        with the terms of Section 20 of the Sublease.

     f. Except as specifically provided herein, all other terms of the Sublease
        shall remain unaltered.
<PAGE>

If the foregoing is acceptable, please sign below where indicated to acknowledge
acceptance of this Letter Agreement by Sublessee.

                              Very truly yours,

                              /s/ Thomas A. Schreck
                              ---------------------

                              Thomas A. Schreck
                              Chief Financial Officer

APPROVED AND ACCEPTED:

Ciena Corporation:

By /s/ Jim Griffin
   ---------------

Title Vice President, Manufacturing
      -----------------------------

Date  November 29, 1999
      -----------------


ACKNOWLEDGED AND CONSENT GRANTED:
Provided that this Sublease Agreement does not modify or change in anyway the
Excess Rents due DeAnza as described in letter dated July 13, 1999

De Anza Enterprises, Ltd.

By /s/ Wade H. Hover
   ------------------------

Title Manager
      ---------------------

Date November 30, 1999
     ----------------------

                                      -2-
<PAGE>

                                   SUBLEASE
                                   --------


     THIS SUBLEASE ("Sublease") is dated for reference purposes as of March 10,
1999, and is made by and between Durect Corporation, a Delaware corporation
("Sublessor"), and Lightera Networks, Inc., a Delaware corporation
("Sublessee").  Sublessor and Sublessee hereby agree as follows:

     1.  Recitals:  This Sublease is made with reference to the fact that De
         --------
Anza Enterprises, as landlord ("Master Lessor"), and Sublessor, as tenant,
entered into that certain Modified Net Single Tenant Lease Agreement dated
February 18, 1999 (the "Master Lease"), for the lease of certain real property
located at 10240 Bubb Road, Cupertino, California (the "Master Premises").  A
copy of the Master Lease is attached hereto as Exhibit A.  Capitalized terms
                                               ---------
used and not defined herein shall have the meaning ascribed to them in the
Master Lease.

     2.  Subleased Premises:  Subject to the terms and conditions of this
         ------------------
Sublease, Sublessor hereby subleases to Sublessee, and Sublessee hereby
subleases from Sublessor, a portion of the building located on the Master
Premises, which portion is deemed to contain 11,072 rentable square feet  and is
more particularly described on Exhibit B attached hereto and incorporated herein
                               ---------
by reference (hereinafter, the "Subleased Premises").

         A.  Shared Space.  The space identified as "common area" on Exhibit B
             ------------                                            ---------
shall constitute "Shared Space".  All space within the Master Premises other
than the Subleased Premises and the Shared Space is reserved for the exclusive
use of Sublessor or Sublessor's other tenants, if any.  Subject to the terms and
conditions set forth herein, Sublessee and its employees, agents and invitees
shall have the non-exclusive right with Sublessor and its employees, agents and
invitees to use the Shared Space, except that Sublessee shall only be entitled
to non-exclusive use of thirty (30) parking spaces located on the Master
Premises.  Sublessor makes no warranty express or implied with respect to the
condition of the Shared Space or any equipment located therein.  Sublessee shall
be responsible for any damage to the Shared Space caused by Sublessee or its
employees, agents, invitees or contractors.  Sublessor shall be responsible for
any damage to the Shared Space caused by Sublessor or its employees, agents,
invitees or contractors. Sublessor may from time to time promulgate reasonable
rules and regulations for the care and orderly management of the Shared Space
and the safety of Sublessor, Sublessee and their employees, agents and invitees.
Such rules and regulations shall be binding upon Sublessee upon delivery of a
copy thereof to Sublessee, and Sublessee agrees to abide by such rules and
regulations.

     3.  Term:
         ----

         A.  Term.  The term (the "Term") of this Sublease shall be for the
             ----
period commencing on the later of: (i) March 15,1999 or (ii) the date by which
the Master Lessor's consent to the Sublease is obtained (the "Commencement
Date") and ending twenty-four (24) months thereafter ("Expiration Date"), unless
this Sublease is sooner terminated pursuant to its terms or the Master Lease is
sooner terminated pursuant to its terms.

         B.  No Option to Extend.  Sublessee shall have no option to extend the
             -------------------
Term of this Sublease.  However, if at any time during the Term, Sublessor, in
its sole and absolute discretion, determines that it desires to sublet, rather
than occupy, the Subleased Premises after the expiration date of this Sublease,
and if Sublessee is not then in default (or would not then be in default but for
the pendency of any grace period) under this Sublease, then prior to offering
the Subleased Premises to any third party, Sublessor shall give Sublessee
written notice of such determination to Sublessee (the "Offer Notice").  The
Offer Notice shall state the terms on which Sublessor is willing to sublease the
Subleased Premises after the expiration of the Term.  If, within ten (10) days
after receipt of Sublessor's notice, Sublessee agrees in writing to sublease
<PAGE>

the Subleased Premises upon such terms or such other terms as are mutually
acceptable to Sublessor and Sublessee, then Sublessor and Sublessee shall
execute a sublease upon such terms within twenty (20) days after Sublessee's
receipt of Sublessor's Offer Notice. If Sublessee does not deliver its notice of
intent to sublease the Subleased Premises within said ten (10)-day period, or if
Sublessor and Sublessee do not enter into a fully executed sublease within said
twenty (20)-day period, then this right of first offer to sublease shall lapse
and be of no further force or effect; in such event, Sublessor shall have the
right to sublease the Subleased Premises to a third party on any other terms
more or less favorable than those offered herein to Sublessee. This right of
first offer is personal to Sublessee and is not transferable.

     4.  Rent:
         ----

         A.  Base Month Rent.  Commencing on the Commencement Date and
             ---------------
continuing throughout the initial term of this Sublease, Sublessee shall pay
monthly rent ("Base Monthly Rent") to Sublessor in the amount of Twenty-six
Thousand Eight Hundred and Eighteen Dollars and Sixty Cents  ($26,818.60), the
amount of $1000 of which shall be attributable to Sublessee's rental of certain
office furniture owned by Sublessor, an inventory of which shall be agreed upon
by Sublessee and Sublessor and attached hereto as Exhibit C no later than ten
(10) days after the Commencement Date.  Base Monthly Rent and Additional Rent,
as defined in Paragraph 4.B below, (collectively, hereinafter "Rent") shall be
paid in advance on or before the first (1st) day of each month.  Rent shall be
payable without notice or demand and without any deduction, offset, or, except
as otherwise provided herein, abatement, in lawful money of the United States of
America.  Rent shall be paid directly to Sublessor at 10240 Bubb Road,
Cupertino, California, Attention: Chief Financial Officer, or such other address
as may be designated in writing by Sublessor.

         B.  Additional Rent.  All monies other than Base Monthly Rent required
             ---------------
to be paid by Sublessee under this Sublease, including, without limitation, (i)
all amounts payable by Sublessor to the Master Lessor with respect to or
reasonably allocate to the Subleased Premises (including, without limitation,
Sublessee's Pro Rata Share of Real Property Taxes as defined in Article 15 of
the Master Lease)  (ii) Sublessee's share of costs for Utilities (as set forth
in Paragraph 8 below), (iii) Sublessee's Pro Rata Share of costs of insurance
premiums and deductibles incurred by Sublessor for insurance maintained by
Sublessor pursuant to Article 23 of the Master Lease, and (iv) Sublessee's Pro
Rata Share of Maintenance Expenses (as defined in Paragraph 7 hereof), shall be
deemed additional rent ("Additional Rent") and shall be payable within twenty
(20) days after receiving an invoice from Sublessor, except that Sublessee's Pro
Rata Share of Real Property Taxes shall be paid within ten (10) days after
receiving Sublessor's invoice.  The term "Sublessee's Pro Rata Share" shall mean
that amount, expressed as a percentage, equal to the number of square feet
included in the Subleased Premises divided by the number of square feet in the
building located on the Master Premises.  The parties hereto acknowledge that
except as otherwise provided herein, Sublessee's Pro Rata Share is thirty-seven
percent (37%).  Sublessee and Sublessor agree, as a material part of the
consideration given by Sublessee to Sublessor for this Sublease, except as
otherwise provided herein, Sublessee shall pay Sublessee's Pro Rata Share of all
costs, expenses, taxes, insurance, maintenance and other charges of every kind
and nature arising in connection with the Master Lease or the Subleased Premises
(excluding, however, costs to the extent arising from (i) any default by
Sublessor, through no fault of Sublessee, under the Master Lease or this
Sublease, or (ii) Sublessor's or its agents', employees' or contractors'
negligence or willful misconduct), such that Sublessor shall receive, as net
consideration for this Sublease, full reimbursement thereof to the extent
applicable to the Subleased Premises. Notwithstanding the foregoing, in the
event any Additional Rent is incurred for Sublessee's sole benefit or as a
result of Sublessee's request for certain services (i.e., extra hours' charges,
etc.) or otherwise, Sublessee shall pay the entire cost thereof, and such
charges shall not be pro rated between Sublessor and Sublessee.
<PAGE>

     Sublessee, and not Sublessor, shall be responsible for (i) the prompt and
timely payment of any personal property taxes or assessments levied against
Sublessee's personal property improvements, alterations or trade fixtures
located within the Subleased Premises, (ii) any telephone service provided to
the Subleased Premises during the Term, and (iii) any permit, license,
governmental fees or charges arising out of Sublessee's specific use and
operation of the Subleased Premises.

     Upon the execution of the Lease by Sublessee, Sublessee shall pay to
Sublessor Base Month Rent for the month of March, 1999 in the amount of
$13,409.30 in immediately available funds.

     5.  Security Deposit:  Upon execution hereof, Sublessee shall deposit with
         ----------------
Sublessor the sum of Twenty-Six Thousand Eight Hundred and Eighteen Dollars and
Sixty Cents  ($26,818.60) (the "Security Deposit"), in cash, as security for the
performance by Sublessee of the terms and conditions of this Sublease.  If
Sublessee defaults (beyond any applicable notice and cure period) with respect
to any provision of this Sublease, then Sublessor may draw upon, use, apply or
retain all or any portion of the Security Deposit for the payment of any Rent or
other charge in default, for the payment of any other sum which Sublessor has
become obligated to pay by reason of Sublessee's default, or to compensate
Sublessor for any loss or damage which Sublessor has suffered thereby.  If
Sublessor so uses or applies all or any portion of the Security Deposit, then
Sublessee, within ten (10) days after receipt of demand by Sublessor therefor,
shall deposit cash with Sublessor in the amount required to restore the Security
Deposit to the full amount stated above.  Sublessor may commingle the Security
Deposit with its own funds and Sublessee shall not be entitled to interest on
the Security Deposit.  Within thirty (30) days after the expiration of this
Sublease and Sublessee's vacation of the Subleased Premises, Sublessor shall
return to Sublessee so much of the Security Deposit as has not been applied by
Sublessor pursuant to this Paragraph, or which is not otherwise required to cure
Sublessee's defaults.

     6.  Holdover: In the event that Sublessee does not surrender the Subleased
         --------
Premises in accordance with the terms of this Sublease, Sublessee shall
indemnify, defend and hold harmless Sublessor from and against all loss, claims,
liabilities and damages resulting from Sublessee's delay in surrendering the
Subleased Premises in the condition required under the terms of this Sublease
and shall pay to Sublessor holdover rent equal to one hundred fifty percent
(150%) of Rent payable hereunder.

     7.  Repairs:
         -------

         A.  The parties acknowledge and agree that Sublessee is subleasing the
Subleased Premises on an "as is" basis, and that Sublessor has made no
representations or warranties, express or implied, with respect to the Subleased
Premises, whatsoever, including, without limitation, any representation or
warranty as to the suitability of the Subleased Premises for Sublessee's
intended use, provided, however, Sublessor hereby agrees that the roof membrane
on the Master Premises shall be replaced at no cost to Sublessee within twelve
(12) months following the Commencement Date.  Sublessee shall, at its sole cost
and expense, keep and maintain in good condition, repair and replace, the
Subleased Premises and every part thereof (including, without limitation,
improvements constructed by or for the benefit of Sublessee); provided, however,
that Sublessee shall not be required to perform (i) any repair, maintenance or
improvements to the heating, ventilating, air conditioning, electrical, water,
sewer, and plumbing systems which do not exclusively serve the Subleased
Premises, it being understood that Sublessor shall be responsible for the repair
and maintenance of any building systems which serve the entire Master Premises
(except as otherwise set forth in the Master Lease) and Sublessee shall be
responsible for the repair and maintenance of any building systems which
exclusively serve the Subleased Premises, or (ii) any maintenance or repair
obligations to the Subleased Premises which are required to be performed by
Sublessor under this Sublease or Master Lessor under the Master Lease.  If any
repair, maintenance or improvements are (i) required to be performed by
Sublessor under the Master Lease and not required to be performed by Sublessee
hereunder, or (ii) required to be paid for by Sublessor under the Master Lease
(including, without limitation, the cost of repairs set forth in Section 18.C of
the Master Lease and the cost of any maintenance contracts required to be
carried by Sublessor under the Master Lease), Sublessee shall reimburse
Sublessor
<PAGE>

for Sublessee's pro rata share of costs incurred by Sublessor to perform or to
pay for the foregoing (collectively "Maintenance Expenses") within twenty (20)
days after receiving an invoice therefor from Sublessor; provided, however, that
Sublessee shall have no obligation to reimburse Sublessor for any Maintenance
Expenses applicable to building equipment or systems exclusively serving any
portion of the Master Premises other than the Subleased Premises and Shared
Space. Notwithstanding anything to the contrary contained in this Sublease,
Sublessor shall have no obligation to perform any repairs or any other
obligation of Master Lessor required to be performed by Master Lessor under the
terms of the Master Lease (including, without limitation Master Lessor's
obligations under Articles 17, 24 and 25 of the Master Lease and Master Lessor's
obligation to comply with laws) and Sublessee shall look solely to Master Lessor
for performance of said obligations; provided, however, Sublessor shall request
performance of the same in writing from Master Lessor promptly after being
requested to do so by Sublessee, and shall use Sublessor's reasonable good faith
efforts (provided Sublessee pays all costs incurred by Sublessor in connection
therewith, unless the matter at issue also affects the portion of the Master
Premises retained for the exclusive use of Sublessor, in which event Sublessee
shall only be required to pay an equitable share of such costs as reasonably
determined by Sublessor) to obtain Master Lessor's performance.

         B.  Notwithstanding anything to the contrary contained in this
Sublease, (i) there shall be no abatement of Rent or liability of Sublessor on
account of any (a) injury or interference with Sublessee's business (including
loss of profits) with respect to any improvements, alterations or repairs made
by Sublessor to the Subleased Premises or Master Premises or any part thereof or
(b) the cessation of any utilities supplied to the Subleased Premises or the
limitation, curtailment, rationing or restrictions required by and governmental
authority on the use of water, electricity, or any other form of energy serving
the Subleased Premises, and (ii) Sublessor shall not be responsible for repairs
required by an accident, fire or other peril, or for damage caused to any part
of the Subleased Premises or Master Premises by any act, negligence or omission
of Sublessee or its agents, contractors, employees or invitees.  It is an
express condition precedent to all obligations of Sublessor to repair and
maintain the Subleased Premises that Sublessee shall have notified Sublessor of
the need for such repairs and maintenance, whereupon Sublessor shall promptly
commence and diligently prosecute its repair obligations.  Sublessee hereby
waives the benefits of any statute which would afford Sublessee the right to
make repairs at Sublessor's expense including but not limited to Sections 1941
and 1942 of the Civil Code of California, or to terminate this Sublease because
of Sublessor's failure to keep the Subleased Premises or Master Premises in good
order, condition and repair.

     8.  Utilities:
         ---------

         A.  The parties acknowledge that other than the Subleased Premises to
be occupied by Sublessee hereunder, the Shared Space, and that portion of the
Master Premises occupied by Sublessor consisting of 10,421 square feet (as shown
on Exhibit B hereto), the remaining portion of the Master Premises ("Area W1"
and "Area W2" as shown on Exhibit B hereto) shall be used solely for warehouse
and storage use, and therefore solely with regard to allocation of the cost of
Utilities, Sublessee's share shall be fifty-one percent (51%) of the costs
incurred by Sublessor for all Utilities set forth in Article 16 of the Master
Lease, which amount shall be payable by Sublessee to Sublessor as Additional
Rent.  Sublessor agrees that heating and air conditioning shall not be provided
to Area W1 and Area W2 without prior written notice to Sublessee.  In the event
Sublessor desires to: (a) change the use of Area W1 or Area W2 to any other use
other than warehouse and storage use or (b) provide heating or air conditioning
to Area W1 or W2, then Sublessor shall provide prior written notice to
Sublessee, in which event Sublessor and Sublessee shall agree to an equitable
allocation of the cost of Utilities.

         B.  Sublessor shall provide air conditioning to the Subleased Premises
consistent with the normal capacity (as opposed to maximum capacity) of the
current air conditioning system in the Master Premises Monday through Friday
8:00 a.m. to 6:00 p.m. and Saturday from 8:00 a.m. to 12:00 p.m., Sundays
<PAGE>

and holidays excepted. Should Tenant use such services in excess of the
foregoing or at hours other than those listed above, Sublessor reserves the
right to charge Sublessee for such excess use as Additional Rent and may charge
Sublessee as Additional Rent Sublessor's actual costs (as reasonably determined
by Sublessor) in providing such excess services. Sublessor shall provide to the
Subleased Premises electric power consistent with normal office use for lighting
and small office machines such as desktop computers, copiers and fax machines.
In addition to Sublessee's Pro Rata Share of utilities set forth hereinabove,
Sublessee shall pay to Sublessor the cost of excessive electricity consumed by
Sublessee as determined by meter, or if not metered, as otherwise reasonably
estimated by Sublessor, plus any actual reasonable accounting expenses incurred
by Sublessor in connection with said determination. Sublessor may cause the
Subleased Premises to be separately metered at Sublessee's expense, including
without limitation, the cost of installing, maintaining, repairing and replacing
such meters. Notwithstanding anything to the contrary contained herein,
Sublessee shall have no obligation to pay for all or any portion of any
excessive utility usage by Sublessor.

     9.  Indemnity:
         ---------

         A.  Sublessee shall indemnify, defend with counsel reasonably
acceptable to Sublessor, protect and hold Sublessor harmless from and against
any and all claims, liabilities, judgments, causes of action, damages, costs and
expenses (including, without limitation, reasonable attorneys' and experts'
fees), to the extent caused by or arising in connection with: (i) the use or
occupancy by Sublessee or its agents, employees, contractors or invitees of the
Subleased Premises or the condition of the Subleased Premises; (ii) the
negligence or willful misconduct of Sublessee or its agents, employees,
contractors or invitees, except to the extent caused by the negligence or
willful misconduct of Sublessor or its authorized employees, agents or
contractors; (iii) a breach of Sublessee's obligations under this Sublease; and
(iv) a breach (through no fault of Sublessor) of Sublessee's obligations under
the Master Lease to the extent such obligations are incorporated herein by this
Sublease.  Sublessee's indemnification of Sublessor shall survive termination of
this Sublease.

         B.  Sublessor shall indemnify, defend with counsel reasonably
acceptable to Sublessee, protect and hold Sublessor harmless from and against
any and all claims, liabilities, judgments, causes of action, damages, costs and
expenses (including, without limitation, reasonable attorneys' and experts'
fees), to the extent caused by or arising in connection with:  (i) the
negligence or willful misconduct of Sublessor or its agents, employees,
contractors or invitees; or (ii) a breach (through no fault of Sublessee) of
Sublessor's obligations as "Tenant" under the Master Lease to the extent such
obligations are not incorporated herein as obligations of Sublessee under this
Sublease.  Sublessor's indemnification of Sublessee shall survive termination of
this Sublease.

     10. Right to Cure Defaults:
         ----------------------

         A.  If Sublessee fails to pay any sum of money to Sublessor, or fails
to perform any other act on its part to be performed hereunder, then Sublessor
may, but shall not be obligated to, after passage of any applicable notice and
cure periods, make such payment or perform such act.  All such sums paid, and
all reasonable costs and expenses of performing any such act, shall be deemed
Additional Rent payable by Sublessee to Sublessor within ten (10) days after
receipt of demand, together with interest thereon at the rate set forth in
Article 34 of the Master Lease (the "Interest Rate") from the date of the
expenditure until repaid.

         B.  If Sublessor is in default (beyond the applicable notice and cure
period) of any of its monetary obligations under the Master Lease, then
Sublessee may, at its option, cure such default, and Sublessee shall be entitled
to collect promptly from Sublessor, Sublessee's reasonable expenses in so doing;
provided, however, that (i) Master Lessor accepts such performance by Sublessee
on behalf of Sublessor, (ii) if Sublessor notifies Sublessee that it disputes
any amount demanded by Master Lessor, Sublessee shall not make any such payment
to Master Lessor unless Master Lessor has provided a three-day notice to pay
such
<PAGE>

amount or forfeit the Master Lease, and (iii) Sublessee shall have provided
Sublessor with at least two (2) business days' written notice of such intention
to cure, and Sublessor shall not cure such default within two (2) business days
after receiving such notice. Additionally, if Sublessor fails to perform any of
its repair and maintenance obligations hereunder within a reasonable time, but
in no event later than thirty (30) days after Sublessor's receipt of written
notice from Sublessee (or such longer period of time if such default cannot
reasonably be cured within said thirty (30)-day period, provided Sublessor
commences such cure within said thirty (30)-day period and thereafter diligently
prosecutes such cure to completion), Sublessee may perform such repair and
maintenance work. If Sublessee so performs such repair and maintenance work, the
full amount of the reasonable and actual cost and expense incurred by Sublessee
shall be owed by Sublessor to Sublessee, and Sublessor shall within ten (10)
days after its receipt of written demand from Sublessee pay to Sublessee the
full amount thereof, it being understood, however, that Sublessee may enforce
its right to such reimbursement by legal action, if necessary, but in no event
shall Sublessee be entitled to offset or otherwise deduct such amounts from
Rent.

     11.  Assignment and Subletting: Subject to the terms of Article 26 of the
          -------------------------
Master Lease, incorporated herein, as modified by the terms of this Sublease,
Sublessee may not assign this Sublease, sublet the Subleased Premises, transfer
any interest of Sublessee therein or permit any use of the Subleased Premises by
another party (collectively, "Transfer"), without the prior written consent of
Sublessor, which consent shall not be unreasonably withheld, and Master Lessor.
A consent to one Transfer shall not be deemed to be a consent to any subsequent
Transfer.  Any Transfer without such consent shall be void and, at the option of
Sublessor, shall terminate this Sublease.  Sublessor's waiver or consent to any
assignment or subletting shall be ineffective unless set forth in writing, and
Sublessee shall not be relieved from any of its obligations under this Sublease
unless the consent expressly so provides.  As a condition of granting its
consent to any Transfer, Sublessor may require Sublessee to pay to Sublessor
fifty percent (50%) of all Excess Rents received by Sublessee which remain after
the portion of such Excess Rents which is payable to Master Lessor under the
Master Lease is deducted therefrom.  As used herein, the term "Excess Rents"
shall mean all Rents and other consideration payable by a subtenant or assignee
to Sublessee in connection with the Transfer (as more particularly described in
Section 26 F. of the Master Lease), less any brokerage commissions, costs
incurred by Sublessee with respect to alterations or improvements made to the
portion of the Subleased Premises that is the subject of the Transfer, and
reasonable attorneys' fees incurred by Sublessee in connection with the
Transfer.  Notwithstanding anything to the contrary contained in this Sublease
or in the Master Lease, (i) Sublessee may assign this Sublease or sublet the
Premises, or any portion thereof, without Sublessor's consent, to (a) any entity
which controls, is controlled by, or is under common control with Sublessee, (b)
to any entity which results from a merger of, reorganization of, or
consolidation with Sublessee, or (c) to any entity which acquires substantially
all of the stock or assets of Sublessee, as a going concern, with respect to the
business that is being conducted in the Premises; provided that in each of the
foregoing Transfers, the net worth of the surviving entity is equal to or
greater than that of the Sublessee immediately prior to the date of the
Transfer, (ii) Sublessee shall reimburse Sublessor and Master Lessor for all
costs and expenses incurred by them in considering any request by Sublessee to a
Transfer, and (iii) a bona fide public or private offering of the capital stock
of Sublessee shall not be deemed a Transfer.

     12.  Use:
          ---
          A.   Sublessee may use the Subleased Premises for general office
purposes, final assembly to configure equipment to customers order(s) and final
quality assurance testing and for no other use without the express written
consent of Sublessor.

          B.  Sublessee shall not use, store, keep, handle, manufacture,
transport, release, discharge, emit or dispose of any Hazardous Materials (as
defined in the Master Lease) in, on, under, about, to or from the Subleased
Premises without the prior written consent of Sublessor; provided, however, that
Sublessee may, without Sublessor's consent, use, in compliance with all
applicable laws, normal types and quantities of Hazardous Materials typically
used in connection with general purpose offices (such as
<PAGE>

copier toner, janitorial supplies and the like). Without limiting the generality
of the foregoing, Sublessee, at its sole cost, shall comply with all laws
relating to Hazardous Materials. Sublessee shall indemnify, defend with counsel
reasonably acceptable to Sublessor and hold Sublessor harmless from and against
all claims, actions, suits, proceedings, judgments, losses, costs, personal
injuries, damages, liabilities, deficiencies, fines, penalties, damages,
reasonable attorneys' fee and consultants' fees, investigations,
detoxifications, remediations, removals, and expenses of every type and nature,
to the extent caused by the use, storage, handling, manufacture, transportation,
release, discharge, emission or disposal of Hazardous Materials on or about the
Subleased Premises or Master Premises by Sublessee or its agents, employees,
contractors or invitees. Sublessor shall indemnify, defend with counsel
reasonably acceptable to Sublessee and hold Sublessee harmless from and against
all claims, actions, suits, proceedings, judgments, losses, costs, personal
injuries, damages, liabilities, deficiencies, fines, penalties, damages,
reasonable attorneys' fee and consultants' fees, investigations,
detoxifications, remediations, removals, and expenses of every type and nature,
to the extent caused by the use, storage, handling, manufacture, transportation,
release, discharge, emission or disposal of Hazardous Materials on or about the
Subleased Premises or Master Premises by Sublessor or its agents, employees,
contractors or invitees.

          C.  Sublessee shall not, without the prior written consent of
Sublessor, store any materials, supplies, finished or unfinished products or
articles of any nature on any area of the Master Premises (including outside the
building) except on the Subleased Premises. Sublessor shall not, without the
prior written consent of Sublessee, store any materials, supplies, finished or
unfinished products or articles of any nature on the Subleased Premises.
Sublessee shall not do or permit anything to be done in, on or about the
Subleased Premises which would (i) injure the Subleased Premises, or (ii)
vibrate, shake, overload, or impair the efficient operation of the Subleased
Premises or any portion of the Master Premises or the sprinkler systems,
heating, ventilating or air conditioning equipment, or utilities systems located
therein. Sublessee shall comply with all reasonable rules and regulations
promulgated from time to time by Sublessor or Master Lessor.

The obligations of Sublessor and Sublessee under this Paragraph 12 shall survive
the expiration or earlier termination of the Term.

     13.  Effect of Conveyance: As used in this Sublease, the term "Sublessor"
          --------------------
means the holder of the Tenant's interest under the Master Lease.  In the event
of any assignment, transfer or termination of the Tenant's interest under the
Master Lease, which assignment, transfer or termination may occur at any time
during the Term hereof in Sublessor's sole discretion, Sublessor shall be and
hereby is entirely relieved of all covenants and obligations first accruing from
and after the date of such transfer so long as such transferee agrees to assume
and carry out all covenants and obligations thereafter to be performed by
Sublessor hereuder.  Sublessor shall transfer and deliver any security of
Sublessee to the transferee of the Tenant's interest under the Master Lease, and
thereupon Sublessor shall be discharged from any further liability with respect
thereto.

     14.  Delivery.  This Sublease shall not be void or voidable, nor shall
          --------
Sublessor be liable to Sublessee for any loss or damage by reason of delays in
the Commencement Date or delays in Sublessor delivering the Subleased Premises
to Sublessee for any reason whatsoever; provided, however, that in the event
that Sublessor does not deliver the Subleased Premises on or before April 1,
1999, then Sublessee may by written notice delivered to Sublessor no later than
April 10, 1999 elect to terminate this Sublease.

     15.  Improvements: No alterations or improvements shall be made to the
          ------------
Subleased Premises, except in accordance with this Sublease and the Master
Lease, and with the prior written consent, when required, of both Master Lessor
and Sublessor.  Sublessor shall not be required to provide a tenant improvement
allowance to Sublessee in connection with Sublessee's construction of any
improvements to the Subleased Premises.

     16.  Release and Waiver of Subrogation: Notwithstanding anything to the
          ---------------------------------
contrary in this Sublease, Sublessor, Sublessee and Master Lessor (by reason of
its consent hereto) hereby release each other and their respective employees,
agents and assigns from any damage to property or loss of any kind which is
<PAGE>

caused by or results from any risk insured against under any property insurance
policy carried by any of such parties or any risk which would normally be
covered by so called "all risk" extended coverage property insurance, without
regard to the negligence or willful misconduct of the party so released.  Each
party shall use reasonable efforts to cause each insurance policy obtained by it
to provide that the insurer waives all right of recovery against the other party
and its agents and employees in connection with any damage or injury covered by
the policy, and each party shall notify the other party if it is unable to
obtain a waiver of subrogation.  Sublessor shall not be liable to Sublessee, nor
shall Sublessee be entitled to terminate this Sublease or to abate Rent for any
reason, including, without limitation, (i) failure or interruption of any
utility system or service; or (ii) failure of Master Lessor to maintain the
Subleased Premises or the Master Premises as may be required under the Master
Lease.  The obligations of Sublessor and Sublessee shall not constitute the
personal obligations of the officers, directors, trustees, partners, joint
venturers, members, owners, stockholders or other principals or representatives
of their respective business entity.  To the extent that rent is abated with
respect to the Subleased Premises under the Master Lease, Sublessee's rental
obligations hereunder shall be abated.

     17.  Insurance: Sublessee shall, with respect to this Sublease, obtain and
          ---------
keep in full force and effect, at Sublessee's sole cost and expense, during the
Term the same types and amounts of insurance coverage required to be carried by
the "Tenant" under the Master Lease, except that instead of the building
insurance coverages set forth in Sections 23 B.(3), (4), (5) and (6), Sublessee
shall carry (in accordance with the requirements set forth in Article 23 of the
Master Lease, as incorporated herein) fire and property damage insurance in so-
called "all risk" form insuring Sublessee's personal property, inventory,
improvements and alterations to the Subleased Premises made by Sublessee, and
trade fixtures within the Subleased Premises, for the full replacement cost
thereof.  Sublessee shall include Sublessor and Master Lessor as an additional
insured in any policy of liability insurance carried by Sublessee in connection
with this Sublease.

     18.  Default: Sublessee shall be in material default of its obligations
          -------
under this Sublease if any of the following events occur:

          A.  Sublessee fails to pay any Rent when due, when such failure
continues for five (5) days after written notice from Sublessor to Sublessee
that any such sum is due; or

          B.  Sublessee fails to perform any term, covenant or condition of this
Sublease (except those requiring payment of Rent) and fails to cure such breach
within fifteen (15) days after delivery of a written notice specifying the
nature of the breach; provided, however, that if more than fifteen (15) days are
reasonably required to remedy the failure, then Sublessee shall not be in
default if Sublessee commences the cure within the fifteen (15) day period and
thereafter completes the cure within thirty (30) days after the date of the
notice; or

          C.  Sublessee makes a general assignment of its assets for the benefit
of its creditors, including attachment of, execution on, or the appointment of a
custodian or receiver with respect to a substantial part of Sublessee's property
or any property essential to the conduct of its business; or

          D.  Sublessee abandons the Subleased Premises; or

          E.  A petition is filed by or against Sublessee under the bankruptcy
laws of the United States or any other debtors' relief law or statute, unless
such petition is dismissed within sixty (60) days after filing; or

          F.  A court directs the winding up or liquidation of Sublessee; or

          G.  A substantial part of Sublessee's property or any property
essential to the conduct of its business is attached or executed upon and not
released from the attachment or execution within sixty (60) days; or
<PAGE>

          H.  A custodian or receiver is appointed for a substantial part of
Sublessee's property or any property essential to the conduct of its business
and not discharged within sixty (60) days; or

          I.  Sublessee commits any other act or omission which constitutes a
default under the Master Lease, which has not been cured after delivery of
written notice and passage of the applicable grace period provided in the Master
Lease as modified, if at all, by the provisions of this Sublease.

     19.  Remedies: In the event of any default by Sublessee, Sublessor shall
          --------
have all remedies provided to the "Landlord" in the Master Lease (including
those remedies set forth in Article 27 of the Master Lease, except that the time
periods referred to therein shall be reduced to correspond to the cure periods
set forth in this Sublease) and by applicable law.  Sublessor may resort to its
remedies cumulatively or in the alternative.

     20.  Surrender: On or before the Expiration Date or any sooner termination
          ---------
of this Sublease, Sublessee shall remove all of its trade fixtures, personal
property and alterations constructed by Sublessee in the Subleased Premises
which are required to be removed under the terms of this Sublease and shall
surrender the Subleased Premises to Sublessor in the condition required by
Section 13 of the Master Lease and with the furniture listed on Exhibit C
accounted for and in the condition existing as of the Commencement Date, normal
wear and tear expected.  If the Subleased Premises are not so surrendered, then
Sublessee shall be liable to Sublessor for all costs incurred by Sublessor in
returning the Subleased Premises to the required condition, plus interest
thereon at the Interest Rate.

     21.  Broker: Each party hereto represents and warrants that it has dealt
          ------
with no broker, in connection with this Sublease and the transactions
contemplated herein, except Corporate Real Estate Consulting and Cornish & Carey
Commercial.  Each party shall indemnify, protect, defend and hold the other
party harmless from all costs and expenses (including reasonable attorneys'
fees) arising from or relating to a breach of the foregoing representation and
warranty.  Sublessor and Norian Corporation shall pay any brokerage commissions
which might be due to Corporate Real Estate Consulting in accordance with
Sublessor and Norian Corporation's respective separate agreements with Corporate
Real Estate Consulting.

     22.  Notices: Unless at least five (5) days' prior written notice is given
          -------
in the manner set forth in this paragraph, the address of each party for all
purposes connected with this Sublease shall be that address set forth below
their signatures at the end of this Sublease.  All notices, demands or
communications in connection with this Sublease shall be properly addressed and
delivered as follows:  (a) personally delivered; or (b) submitted to an
overnight courier service, charges prepaid; or (c) deposited in the mail
(certified, return-receipt requested, and postage prepaid).  Notices shall be
deemed delivered upon receipt, if personally delivered, one (1) business day
after being submitted to an overnight courier service and two (2) business days
after deposit in the United States mail, if mailed as set forth above.  All
notices given to Master Lessor under the Master Lease shall be considered
received only when delivered in accordance with the Master Lease.

     23.  Other Sublease Terms:
          --------------------

          A.  Incorporation By Reference. Except as set forth below and except
              --------------------------
as otherwise provided in this Sublease, the terms and conditions of this
Sublease shall include all of the terms of the Master Lease and such terms are
incorporated into this Sublease as if fully set forth herein, except that: (i)
each reference in such incorporated sections to "Lease" shall be deemed a
reference to this "Sublease"; (ii) each reference to the "Premises" shall be
deemed a reference to the "Subleased Premises"; (iii) each reference to
"Landlord" and "Tenant" shall be deemed a reference to "Sublessor" and
"Sublessee", respectively, except as otherwise expressly set forth herein; (iv)
with respect to work, services, utilities, electricity, repairs (or damage
caused by Master Lessor), restoration, insurance, indemnities, reimbursements,
representations, warranties or the performance of any other obligation of Master
Lessor under the Master Lease, whether or not incorporated herein, the sole
obligation of Sublessor shall be to request the same in writing from Master
Lessor as and when requested to do so by Sublessee, and to use
<PAGE>

Sublessor's reasonable good faith efforts (provided Sublessee pays all costs
incurred by Sublessor in connection therewith, unless the matter at issue also
affects the portion of the Master Premises which is not part of the Subleased
Premises, in which event Sublessee shall only be required to pay an equitable
share of such costs as reasonably determined by Sublessor) to obtain Master
Lessor's performance; (v) with respect to any obligation of Sublessee to be
performed under this Sublease, wherever the Master Lease grants to "Tenant" a
specified number of days to perform its obligations under the Master Lease,
except as otherwise provided herein, Sublessee shall have three (3) fewer days
to perform the obligation, including, without limitation, curing any defaults
(provided, however, that if any cure period provides for three (3) days or less
to perform, Sublessee shall have one (1) business day to perform); (vi) with
respect to any approval required to be obtained from the "Landlord" under the
Master Lease, such consent must be obtained from both Master Lessor and
Sublessor, and the approval of Sublessor may be withheld if Master Lessor's
consent is not obtained; (vii) in any case where the "Landlord" reserves or is
granted the right to manage, supervise, control, repair, alter, regulate the use
of, enter or use the Premises or any areas beneath, above or adjacent thereto,
such reservation or grant of right of entry shall be deemed to be for the
benefit of both Master Lessor and Sublessor; (viii) in any case where "Tenant"
is to indemnify, release or waive claims against "Landlord", such indemnity,
release or waiver shall be deemed to run from Sublessee to both Master Lessor
and Sublessor; (ix) in any case where "Tenant" is to execute and deliver certain
documents or notices to "Landlord", such obligation shall be deemed to run from
Sublessee to both Master Lessor and Sublessor; (x) the following modifications
shall be made to the Master Lease as incorporated herein:

               (a) the following provisions of the Master Lease are not
incorporated herein: Sections 1, 2, 3, 4, 6, 9, 26(I), 28 (last paragraph), 29
(except with respect to Master Lessor), 30, 35 and 42 and Exhibit "B".

               (b) references to "Landlord" in the following provisions shall
mean "Master Lessor" only: Sections 17, 18.C, 24.A (first, third, fifth and
seventh references to "Landlord" only), 24.B, 24.C (first reference), 25.B, and
39 (first sentence of second paragraph).

               (c) the reference to $10,000 in Section 12.A shall be replaced by
$3,000;

               (d) any right to abate rent provided to Sublessee through
incorporation of the provisions of the Master Lease shall not exceed the rent
actually abated under the Master Lease with respect to the Subleased Premises.

          B.  Incorporation of Obligations. This Sublease is and at all times
              ----------------------------
shall be subject and subordinate to the Master Lease and the rights of Master
Lessor thereunder.  Sublessee hereby expressly agrees: (i) to comply with all
provisions of the Master Lease which are incorporated by reference in this
Sublease; and (ii) except as otherwise provided in this Sublease, to perform all
the obligations on the part of the "Tenant" to be performed under the terms of
the Master Lease with respect to the Subleased Premises during the term of this
Sublease.  Sublessor shall perform or cause to be performed all of the
obligations of "Tenant" under the Master Lease, except to the extent such
obligations are incorporated herein as obligations of Sublessee under this
Sublease.  In the event the Master Lease is terminated for any reason,
whatsoever, this Sublease shall terminate simultaneously with such termination;
provided, however, that if, without the fault of Sublessor, the Master Lease
should terminate prior to the expiration of this Sublease, Sublessor shall have
no liability to Sublessee on account of such termination.  In the event of a
conflict between the provisions of this Sublease and the Master Lease, as
between Sublessor and Sublessee, the provisions of this Sublease shall control.
<PAGE>

     24.  Right to Contest: If Sublessor does not have the right to contest any
          ----------------
matter in the Master Lease due to expiration of any time limit that may be set
forth therein or for any other reason, then notwithstanding any incorporation of
any such provision from the Master Lease in this Sublease, Sublessee shall also
not have the right to contest any such matter.

     25.  Covenant of Quiet Enjoyment: Sublessee peacefully shall have, hold and
          ---------------------------
enjoy the Subleased Premises, subject to the terms and conditions of this
Sublease, provided that Sublessee pays all Rent imposed hereunder and otherwise
performs all of Sublessee's covenants and agreements contained herein.

     26.  Conditions Precedent: Notwithstanding anything to the contrary in this
          --------------------
Sublease:  this Sublease and Sublessor's and Sublessee's obligations hereunder
are conditioned upon the written consent of Master Lessor to this Sublease.  If
Sublessor does not receive such consent within thirty (30) days after execution
of this Sublease by Sublessor, then until such time consent is obtained,
Sublessor may terminate this Sublease by giving Sublessee written notice
thereof, and upon such termination, Sublessor shall return to Sublessee its
payment of Base Monthly Rent paid by Sublessee pursuant to Paragraph 4 hereof
and the Security Deposit.

     27.  No Third Party Rights: The benefit of the provisions of this Sublease
          ---------------------
is expressly limited to Sublessor and Sublessee and their respective permitted
successors and assigns.  Under no circumstances will any third party be
construed to have any rights as a third party beneficiary with respect to any of
said provisions.

     28.  Choice of Law; Severability: This Sublease shall in all respects be
          ---------------------------
governed by and construed in accordance with the laws of the State of
California.  If any term of this Sublease is held to be invalid or unenforceable
by any court of competent jurisdiction, then the remainder of this Sublease
shall remain in full force and effect to the fullest extent possible under the
law, and shall not be affected or impaired.

     29.  Amendment: This Sublease may not be amended except by the written
          ---------
agreement of all parties hereto.

     30.  Attorneys' Fees: If either party brings any action or legal proceeding
          ---------------
with respect to this Sublease, the prevailing party shall be entitled to recover
from the other party reasonable attorneys' fees, experts' fees, and court costs.
If either party becomes the subject of any bankruptcy or insolvency proceeding,
then the other party shall be entitled to recover all reasonable attorneys'
fees, experts' fees, and other costs incurred by that party in protecting its
rights hereunder and in obtaining any other relief as a consequence of such
proceeding.

     3.1  Authority to Execute: Sublessee and Sublessor each represent and
          --------------------
warrant to the other that each person executing this Sublease on behalf of each
party is duly authorized to execute and deliver this Sublease on behalf of that
party.

     32.  Counterparts: This Sublease may be executed in one (1) or more
          ------------
counterparts each of which shall be deemed an original but all of which together
shall constitute one (1) and the same instrument.  Signature copies may be
detached from the counterparts and attached to a single copy of this Sublease
physically to form one (1) document.

     33.  ADA:  Sublessor represents to Sublessee that Sublessor has no actual
          ----
knowledge that any portion of the Master Premises does not comply with the
Americans With Disabilities Act (the "ADA").  However, Sublessee acknowledges
that Sublessor has made no inquiry nor done any investigation whatsoever with
regard to ADA compliance.

     34.  Gates:  Sublessor hereby agrees to use its good faith efforts in order
          ------
to cause the gates to the parking lots on the Master Premises to remain open at
all times.  In addition, subject to the consent of the Master Lessor, Sublessee
may, at its cost, remove those gates and that portion of the fencing as
indicated on Exhibit B hereto.

     35.  Demising Space:  Sublessee shall at its cost construct a wall which
          --------------
demises Area W1 and the Subleased Premises as shown on Exhibit B.
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Sublease as of the day
and year first above written.

SUBLESSOR:                             SUBLESSEE:

DURECT CORPORATION, a Delaware         LIGHTERA NETWORKS, INC., a  Delaware
corporation                            corporation

By:  /s/ Thomas A. Schreck             By:  /s/ David E. Chambers
    -------------------------              --------------------------------
Name: Thomas A. Schreck                Name:  David E. Chambers
      ------------------------               ------------------------------

Its:  Chief Financial Officer          Its: Vice President of Engineering &
      -----------------------               -------------------------------
                                            Manufacturing
                                            -------------

    Address:  10240 Bubb Road                    Address:  10201 Bubb Road
    Cupertino, CA  95014                         Cupertino, CA  95014

<PAGE>

                              CONSENT TO SUBLEASE

     Master Lessor hereby acknowledges receipt of a copy of this Sublease, and
consents to the terms and conditions of this Sublease.  Master Lessor represents
and warrants that the Master Lease is in full force and effect and has not been
modified, and to Master Lessor's knowledge, there exists under the Master Lease
no default or event of default by either Master Lessor or Sublessor, nor has
there occurred any event which, with the giving of notice or the passage of time
or both, could constitute such a default or event of default.  By this consent,
Master Lessor shall not be deemed in any way to have entered into the Sublease
or to have consented to any further assignment or sublease.


                           MASTER LESSOR:

                           DE ANZA ENTERPRISES, LTD.


                           By: /s/ Julia Hoover-Smoot
                               -----------------------------------
                           Print Name: Julia Hoover-Smoot
                                       ---------------------------
                           Title: Attorney
                                  --------------------------------
                           Dated: March 18, 1999
                                  --------------------------------
<PAGE>

                                   EXHIBIT A
                                   ---------

                                  MASTER LEASE
                                   (Attached)
<PAGE>

                                   EXHIBIT B
                                   ---------
                               SUBLEASED PREMISES
                                   (Attached)
<PAGE>

                                   EXHIBIT C
                                   ---------
                              FURNITURE INVENTORY


<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------
          Description                          Count                  Tag #
-------------------------------------------------------------------------------------------
<S>                                            <C>                  <C>
Gray Metal File Cabinet - 4 drawer               36                   00153-54, 00205-08,
                                                                      00215, 00220-21,
                                                                      00228, 00235, 00269,
                                                                      00275-80, 00290,
                                                                      00295, 00325,
                                                                      00327-31, 00339-40,
                                                                      00350-51, 00362,
                                                                      00367, 00371-74
-------------------------------------------------------------------------------------------
Dark Blue Metal File Cabinet - 2 drawer           1                   00199
-------------------------------------------------------------------------------------------
Blond Wood Top File Cabinet - 2 drawer            1                   00211
-------------------------------------------------------------------------------------------
Gray/Blond Wood Top Storage Cabinets              3                   00222-00224
-------------------------------------------------------------------------------------------
Burgundy High Back Swivel Office Chairs          41                   00158-59, 00177,
                                                                      00230-31, 00236,
                                                                      00241-47, 00250-66,
                                                                      00273, 00284, 00294,
                                                                      00300, 00303,00310,
                                                                      00313, 00317, 00324,
                                                                      00341, 00347,
                                                                      00354, 00358-59,
                                                                      00368, 00378-, 00382,
                                                                      00386-87, 00390,
                                                                      00393-94
-------------------------------------------------------------------------------------------
Green Office Guest Chairs                         3                   001160-62
-------------------------------------------------------------------------------------------
Burgundy Office Guest Chairs                     52                   00163-76, 00178-97,
                                                                      00267-68, 00285-86,
                                                                      00292-93, 00301-02,
                                                                      00342-43, 00348-49,
                                                                      00360-61, 00369-70,
                                                                      00391-92
-------------------------------------------------------------------------------------------
Gray Metal 5 Shelf Bookshelf                      1                   00326
-------------------------------------------------------------------------------------------
Gray Metal 4 Shelf Bookshelf                      8                   00203-04, 00219,
-------------------------------------------------------------------------------------------
</TABLE>
<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------
                                                                      00229, 00272, 00335,
                                                                      00363, 00375
-------------------------------------------------------------------------------------------
Furniture Inventory
-------------------------------------------------------------------------------------------
Description                                           Count                  Tag #
-------------------------------------------------------------------------------------------
<S>                                            <C>                           <C>
Gray Metal 3 Shelf Bookshelf                               1                00296
-------------------------------------------------------------------------------------------
Gray Metal 2 Shelf Bookshelf                               2                00237, 00291
-------------------------------------------------------------------------------------------
Black Lobby Coffee Table                                   1                00238
-------------------------------------------------------------------------------------------
Lobby Ashtray Canister                                     1                00239
-------------------------------------------------------------------------------------------
Large Oval Blond Wood Conference Table                     1                00240
-------------------------------------------------------------------------------------------
Small Oval Blond Wood Conference Table                     2                00248-49
-------------------------------------------------------------------------------------------
Blond Wood Top Round Table                                 1                00157
-------------------------------------------------------------------------------------------
Gray Round Tables                                          2                00156, 00198
-------------------------------------------------------------------------------------------
Gray Rectangular Table                                     1                00274
-------------------------------------------------------------------------------------------
</TABLE>


Acknowledged by:

Durect Corp:

By:___________________________      Dated:_____________________________


Lightera Networks, Inc.:

By:___________________________      Dated:_____________________________