**Exhibit 10.21**

**PATENT LICENSE AGREEMENT [***]**

This Patent LicenseAgreement (this “Agreement”) is entered into as of May 15, 2007 (the “EffectiveDate”) by and between Avistar Systems UK Limited. a UK corporation, havingoffices at Boston House, 63-64 New Broad Street, London, UK ECZ M1J (“AVUK”),Avistar Communications Corporation, a Delaware corporation, having offices at1875 South Grant Street, Suite 1000, San Mateo, CA 94402 (“AVISTAR”) andRadvision, Ltd., an Israeli corporation having offices at 24 Raoul WallenbergStreet, Tel Aviv 69719 (“RADVISION”). RADVISION and AVUK and AVISTAR areeach a “Party” and collectively the “Parties.”

**RECITALS**

WHEREAS, AVUK is thelegal and beneficial owner of the right to grant sublicense under the CPILicensed Patents described below through a license received from CollaborationProperties, Inc. a Nevada corporation, having offices at 1875 South GrantStreet, Suite 1000, San Mateo, CA 94402 (“CPI”);

WHEREAS, AVUK is willingto grant a nonexclusive license under the CPI Licensed Patents to RADVISION andits Affiliates;

WHEREAS, AVUK and CPI arewholly owned subsidiaries of AVISTAR;

WHEREAS, RADVISIONdesires a nonexclusive license under CPI Licensed Patents subject to the termsand conditions set forth herein; and

WHEREAS, RADVISION andits Affiliates are the owner of certain RADVISION Licensed Patents (as definedherein) and is willing to grant a nonexclusive license under the RADVISIONLicensed Patents.

NOW THEREFORE, theParties agree as follows:

# **1.             Definitions**

# Thefollowing capitalized terms shall have the meanings set forth below.  The use of singular shall include the pluraland vice versa, where appropriate.

## 1.1                                 “Affiliate”shall mean, in the case of AVUK, a Person that is under Control of AVISTAR and,in the case of RADVISION, a Person that is under the Control of RADVISION.  

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## 1.2                                 “BuildingLocal Exchange Carrier System” shall mean a multi-tenant building videonetworking system that provides building-internal video networks and servicesin office towers, industrial parks, hotels, and apartment complexes. Such asystem may include access to broadband carriers, building-internal switches,building internal video storage servers, and building-internal multipoint controlunits.  

## 1.3                                 “Control”shall mean the ownership, directly or indirectly, of more than fifty percent(50%) of the voting securities or other ownership interest of a Person or, withrespect to a limited partnership or other similar Person, its general partneror controlling Person.  A Person shall bean Affiliate only so long as such control exists.

## 1.4                                 “Disputes”shall mean any action, dispute, claim or controversy of any kind, whether incontract or tort, statutory or common law, legal or equitable, now existing orhereafter arising under or in connection with, or in any way pertaining to,this Agreement.

## 1.5                                 “InstantMessaging System” shall mean any system that provides instant messagingcall initiation, login-based call routing, and presence indication. Such asystem may be implemented in hardware, software, or a combination thereof.

## 1.6                                 “CPILicensed Patents” shall mean all patents and patent applications and anypatents issuing therefrom worldwide that have or are entitled to the benefit ofa filing date on or before the Effective Date that are owned or licensable byAVUK as of the Effective Date without the payment of royalties or otherconsideration to an unaffiliated third party. CPI Licensed Patents shallinclude, without limitation, the patents and patent applications set forth inExhibit A.

## 1.7                                 “RADVISIONLicensed Patents” shall mean all patents and patent applications and anypatents issuing therefrom worldwide that have or are entitled to the benefit ofa filing date on or before the Effective Date that are owned or licensable byRADVISION or its Affiliates as of the Effective Date without the payment ofroyalties or other consideration to an unaffiliated third party.

## 1.8                                 “RADVISIONLicensed Products” shall mean Multimedia Communications Systems and/or anyparts or components thereof which are sold by RADVISION or its Affiliates, ortheir dealers, partners, resellers or agents, which are licensed ormanufactured by or for RADVISION or its Affiliates and which are covered by oneor more claims of the CPI Licensed Patents which, absent the license granted toRADVISION hereunder, would infringe a claim of any of the CPI LicensedPatents.  Licensed Products shall notmean Instant Messaging Systems, Building Local Exchange Systems, Voice OverInternet Protocol Systems, Metropolitan Area Network Systems, Data-ProtocolTransmission Carrier Systems, and 

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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##                                                 RADVISIONDeveloper Products except to the extent that any or all of them areincorporated in RADVISION Multimedia Communication Systems.

## 1.9                                 “AVISTARLicensed Products” shall mean Multimedia Communications Systems and/or anyparts or components thereof which are sold by AVISTAR or its Affiliates, ortheir dealers, partners, resellers or agents, which are licensed ormanufactures by or for AVISTAR or its Affiliates and which are covered by oneor more claims of the RADVISION Licensed Patents which, absent the licensegranted to AVISTAR hereunder, would infringe a claim of any of the RADVISION LicensedPatents.  Licensed Products shall notmean Instant Messaging Systems, Building Local Exchange Systems, Voice OverInternet Protocol Systems, Metropolitan Area Network Systems, Data-ProtocolTransmission Carrier Systems, and RADVISION Developer Products except to theextent that any or all of them are incorporated in AVISTAR MultimediaCommunication Systems.

## 1.10                           “MetropolitanArea Network System” shall mean a networking system that providesinterbuilding communications and services in a local geographical regionutilizing cable plant. Such a system may include a multimedia central office,access to broadband carriers, switches, multiplexers, routers, video storageservers, and multipoint control units.

## 1.11                           “Person”shall mean an individual, corporation, partnership, association, trust,incorporated organization, governmental authority, other entity or group (asdefined in Section 13(d)(3) of the Exchange Act of 1934, as amended as of theEffective Date).

## 1.12                           “RADVISIONDeveloper Products” shall mean all RADVISION development tool products,development environment products, and API-oriented software products as usedfor communication signaling protocols, communication transport protocols,communication session protocols, protocol conversion, multiplexing, callcontrol, advanced call control, connection management, multi-line operation,user interface, restart, media encoding/decoding/transcoding, codecinterfacing, endpoint operation, encryption, network security, serveroperation, conference bridge, gateway, gatekeeper, blocking/non-blockingresource management, text and video messaging applications, semantic levelprocessing, message parsing, message transactions, presence, forking,forwarding, message validation, routing, user authentication, account datacollection, code examples, templates, testing, debugging, tracing, analysis, aswell as other similar, related, supporting, and underlying functions pertainingto all of the aforementioned. “RADVISION Developer Products” shall include,without limitation, the RADVISION H.323 Protocol Toolkit, SIP Protocol Toolkit,IMS-SIP Toolkit, Java SIP toolkit, 3G-

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## 324M Toolkit, Advanced RTP/RTCP Toolkit, RTSPClient Toolkit, MEGACO/H.248 Toolkit, MGCP Toolkit, SIP Server Platform,Videophone Terminal Framework, IP Phone and IAD Terminal Framework, and MediaFramework.

## 1.13                           “RADVISION3G-324M Developer Product” shall mean the RADVISION 3G-324 Toolkit asdefined in the Software License Agreement.

## 1.14                            “MultiMedia Communications System” shall mean a system having two or moreendpoints or servers, each designed to work with one or more similar ordissimilar endpoints or servers through network or other connections toimplement a two-way video and/or audio and/or data conference.  Such a system may comprise a support foractive use of a network connection, video and/or audio codec functions, aprocessor for implementing at least connection control functions, and may beimplemented in hardware, software, or a combination thereof. Such a system mayadditionally comprise one or more video monitors, video cameras, audiomicrophones, audio speakers, audio echo cancellation capabilities, networkinterfaces utilizing unshielded twisted pair network cabling, graphical user interfacecapabilities, directories or databases of user information, directories ordatabases of the capabilities of remote equipment, multi-point capabilities,and data conferencing capabilities. Such a system may be implemented in amanner conducive to desktop operation, meeting room operation, or both.

## 1.15                            “VideoStorage or Playback System” shall mean a system comprising video answeringfunctions, video conference recording, video-on-demand, video presentationapplications that include synchronized text or graphics, storage area networkssupporting video, and video storage servers. Such a system may be implementedin hardware, software, or a combination thereof.

## 1.16                           “VoiceOver Internet Protocol System” shall mean two-way voice telephonycommunications utilizing data communications protocols.

# **2.             Grantof Rights to RADVISION**

## 2.1                                 LicenseGrant.  Subject to the terms of thisAgreement and the payment pursuant to Section 6 below, AVUK grants to RADVISIONand its Affiliates a world wide, non-exclusive, and limited license with thelimited right to sublicense (subject to the limitations of 2.3 below) under theCPI Licensed Patents to make, have made (subject to the limitations of Section2.2 below), use, import, offer to sell, sell, lease, license, or otherwisetransfer (whether directly or through resellers, OEMs, partners, distributorsor agents) RADVISION Licensed Products.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## 2.2                                 LimitedHave Made Right. The license granted in Section 2.1 to have products madeby another manufacturer shall only apply when the product manufactured forRADVISION is owned by or licensed by or to RADVISION.

## 2.3                                 NoSublicense Rights.  Except as may beexpressly set forth in this Agreement, RADVISION and its Affiliates shall haveno right to grant any third party any sublicense or other rights under the CPILicensed Patents without the express prior written consent of AVUK.   [***] the [***], and [***] the [***] of this[***], RADVISION and its Affiliates [***], [***] with [***] to [***] under theCPI Licensed Patents [***] as [***] be [***] for the [***] and [***] of, [***]any [***] that [***] not [***] the [***] of, the [***].

## 2.4                               NoOther Rights.  AVUK reserves allrights not expressly granted to RADVISION in this Agreement.  Without limiting the generality of theforegoing sentence (i) no license is granted and no rights are exhausted,either directly or by implication, estoppel or otherwise, to RADVISION or anyother person for the combination or use of any RADVISION Licensed Products with any other item or product that is not aRADVISION Licensed Product [***] theRADVISION Licensed Product would [***]be a [***] or [***] by RADVISION in such [***] and provided further that [***] to the [***]or the [***] of the [***] which [***] [***] by, is [***] to and [***] with the [***]; (ii) no license or covenant is granted under this Agreement for any thirdparty products on a stand alone basis; and (iii) no right or license isgranted herein under any intellectual property (including under any patent,copyrights, trademarks, mask work rights, or trade secret rights) of AVUK orany other Person, other than under the CPI Licensed Patents.

# **3.             AdditionalRights for RADVISION**

## 3.1                                 Covenantnot to Sue.  AVUK, on behalf ofAVISTAR and its Affiliates grants to RADVISION and its Affiliates personal andnon-transferable covenants not to commence or maintain any suit or other actionfor patent infringement against RADVISION and its Affiliates for past or futurepatent infringement for RADVISION Developer Products, [***] its [***] for [***]use of [***]. AVUK [***] that RADVISION Developer Products [***] by [***] to[***] a single [***] and the [***] not to [***] herein [***] to the [***] ofsuch [***] to all such [***]. AVUK and AVISTAR and its Affiliates specificallyreserve all of their rights to assert its patents and other rights against andprovides no covenant not to commence or maintain any suit or other action forpatent infringement against products developed by [***] using or incorporatingall or portions of RADVISION Developer Products.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## 3.2                                 CPI Release forPast Infringement. Subject to the payment set forth in Section 6, AVUK, onbehalf of AVISTAR and its Affiliates which are Affiliates as of the EffectiveDate, as releasor, irrevocably releases RADVISION, its Affiliates which areAffiliates as of the Effective Date and its and their respective distributors,resellers, OEMs, partners, agents, customers and users, mediate and intermediate,from any and all claims of infringement of CPI’s Licensed Patents which claimsare based on acts, which, had they been performed after the Effective Datewould have been licensed under this Agreement.

# **4.             Grantof Rights to AVISTAR**

## 4.1                                 LicenseGrant.  Subject to the terms of thisAgreement RADVISION grants to AVISTAR and its Affiliates a world wide,non-exclusive, and limited license with the limited right to sublicense(subject to the limitations of Section 4.3 below) under the RADVISION Licensed Patentsto make, have made (subject to the limitations of Section 4.2 below), use,import, offer to sell, sell, lease, license, or otherwise transfer (whetherdirectly or through resellers, OEMs, partners or distributors) AVISTAR LicensedProducts.

## 4.2                     Limited HaveMade Right. The license granted in Section 4.1 to have products made byanother manufacturer shall only apply when the product manufactured for AVISTARis owned by or licensed by or to AVISTAR.

## 4.3                                 NoSublicense Rights.  Except as may beexpressly set forth in this Agreement, AVISTAR and its Affiliates shall have noright to grant any third party any sublicense or other rights under theRADVISION Licensed Patents without the express prior written consent ofRADVISION.   [***] the [***], and [***]the [***] of the [***], AVISTAR and its Affiliates [***], [***] with [***] to[***] under the RADVISION Licensed Patents [***] as [***] be [***] for the[***] and [***] of, [***] any [***] that [***] not [***] the [***] of, the[***].

## 4.4                                 NoOther Rights.  RADVISION reserves allrights not expressly granted to AVISTAR in this Agreement.  Without limiting the generality of theforegoing sentence (i) no license is granted and no rights are exhausted,either directly or by implication, estoppel or otherwise, to AVISTAR or anyother person for the combination or use of any AVISTAR Licensed Products with any other item or product that is not a AVISTARLicensed Product [***] the AVISTARLicensed Product would [***] be a [***] or [***] byAVISTAR in such [***] and providedfurther that [***] to the [***] or the [***]of the [***] which is [***] by, is [***]to and [***] with the [***]; (ii) no license or covenant is granted under thisAgreement for any third party products on a stand alone basis; and (iii) noright or license is granted herein under any intellectual property (includingunder any patent, copyrights, trademarks, mask work rights, or trade secretrights) of 

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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##                                                 RADVISIONor any other Person, other than under the RADVISION Licensed Patents.

**5.             Additional Rights For AVISTAR**

## 5.1                                 RADVISIONRelease for Past Infringement. RADVISION, as releasor, on behalf of itself and its Affiliates which areAffiliates as of the Effective Date, irrevocably releases AVISTAR, itsAffiliates which are Affiliates as of the Effective Date and its and theirrespective distributors, customers and users from any and all claims, whetherknown or unknown, of patent infringement occurring on or before the EffectiveDate which claims are based on acts, which, had they been performed after theEffective Date would have been licensed under this Agreement.

# **6.             Payments**

6.1                               Paymentsand Other Consideration.  In partialconsideration of the licenses, releases and other rights granted to RADVISIONand its Affiliates under this Agreement, RADVISION shall pay to AVUK fourmillion United States dollars ($4,000,000). Such payment shall be made beforeJune 30, 2007 by electronic funds transfer to the account specified below.

AVUK AccountInformation:

Bank: [***]

Address: [***]

Company:  Avistar Systems (UK) Limited.

Address: [***]

Swiss Code: [***]

6.2                                 RADVISION shall also grant to AVISTAR and its Affiliates a fully paid-uplicense to the RADVISION 3G-324M Toolkit as of the Effective Date, includingstandard maintenance support at no charge for two years from the EffectiveDate, in accordance with the license agreement set forth as Attachment B.

# **7.             Warrantiesand Representations**

7.1                                 General.Each Party represents and warrants to the other Party as of the Effective Datethat:

(a)           it is a corporationduly organized, validly existing and in good standing under the laws of thestate of its organization;

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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(b)            it has theauthority to (i) enter into this Agreement, (ii) extend the rights, licensesand sublicenses granted to the other Party under this Agreement, and (iii)undertake and fully perform its obligations under this Agreement;

(c)            it is not subjectto a petition for relief under any bankruptcy legislation, it has not made anassignment for the benefit of creditors, it is not subject to the appointmentof a receiver for all or a substantial part of its assets, and it is notcontemplating taking any of the foregoing actions; and

(d)            all necessaryconsents, approvals and authorizations of all regulatory and governmentalauthorities and other Persons required to be obtained by it in connection with(i) the execution and delivery of this Agreement, (ii) its granting of rightsand licenses hereunder, and (iii) the performance of its obligations hereunderhave been obtained.

# 7.2                                 Absenceof Patent Warranties.  Nothing inthis Agreement shall be construed (i) as a warranty or representation byAVUK or RADVISION as to the validity, enforceability or scope of any of theclaims of the Licensed Patents, or (ii) as a warranty or representation thatany Licensed Product, or anything else made, used, sold, imported or otherwisedisposed of under the licenses granted in Section 2 and 4 is, or will be, freefrom infringement of any patents, copyrights, trade secrets, trademarks, or anyother intellectual property or proprietary rights of third parties.

# 7.3                                 NoObligations. AVUK and its Affiliates shall have no obligation hereunder toinstitute any action or suit against any Person for infringement of any of theCPI Licensed Patents or to defend any action or suit brought by a Person thatchallenges or concerns the validity of any of the CPI Licensed Patents.RADVISION shall have no right to institute any action or suit against Personsfor infringement of any of the CPI Licensed Patents. AVUK is not, nor is any ofits Affiliates, required to file any patent application, or to secure anypatent or patent rights, or to maintain any patent in force. RADVISION shallhave no obligation hereunder to institute any action or suit against any Personfor infringement of any of the RADVISION Licensed Patents or to defend anyaction or suit brought by a Person that challenges or concerns the validity ofany of the RADVISION Licensed Patents. AVUK shall have no right to instituteany action or suit against Persons for infringement of any of the RADVISIONLicensed Patents. RADVISION is not, nor is any of its Affiliates, required tofile any patent application, or to secure any patent or patent rights, or tomaintain any patent in force.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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7.4                                 OtherTransactions.  Either Party mayassign, convey, sell, lease, encumber, license, sublicense or otherwisetransfer to a third party any and all of its Licensed Patents provided that anysuch transaction is made subject to all rights and licenses of the other Partyarising from this Agreement and shall not impose any additional obligations onsuch other Party.

# **8.             Disputes**

It is the intent of the Parties and subject to the terminationprovisions of this Agreement that Disputes be resolved expeditiously, amicablyand at the level within each Party’s organization that is most knowledgeableabout the disputed issue. As a result, the Parties agree that all Disputesarising under this Agreement will be resolved by the procedure outlined in thisSection 8:

## 8.1                                 Thecomplaining Party will notify the other Party in writing of the dispute, andthe non-complaining Party will exercise good faith efforts to resolve thematter as expeditiously as possible.

## 8.2                               Inthe event that such matter remains unresolved twenty (20) days after thedelivery of the complaining Party’s written notice, a senior representative ofeach Party will meet or participate in a telephone conference call within ten(10) business days of a request for such a meeting or conference call by eitherParty to resolve the Dispute.

## 8.4                                 Ifthe Parties are unable to reach a resolution of the Dispute after following theabove procedure, any Dispute will be resolved exclusively by bindingarbitration in accordance with the terms of this Section 8.

## 8.5                               Arbitrationproceedings will be administered by the American Arbitration Association (“AAA”)in accordance with the AAA Commercial Arbitration Rules. All Disputes submittedto arbitration will be resolved in accordance with the Federal Arbitration Act(Title 9 of the United States Code). The arbitration will be conducted at alocation in New York, New York selected by the AAA. All discovery activitieswill be expressly limited to matters directly relevant to the dispute beingarbitrated. Judgment upon any award rendered in arbitration may be entered inany court having jurisdiction.

## 8.6                               Arbitratorsmust be active members of the Bar of a U.S. state or retired judges of thestate or federal courts, with expertise in patent law, licensing law and othersubstantive laws, applicable to the subject matter of the Dispute. Any Disputewill be decided by majority vote of a panel of three arbitrators; providedhowever, that all three arbitrators must actively participate in all hearings.Notwithstanding

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## anything herein to the contrary, thearbitrators will be required to make specific, written findings of fact andconclusions of law.

## 8.7                                 Tothe maximum extent practicable, the AAA, the arbitrators and the Parties willtake all action required to conclude any arbitration proceeding within onehundred and eighty (180) days of the filing of the dispute with the AAA. Noarbitrator or other party to an arbitration proceeding may disclose theexistence, content or results thereof, except for disclosures of information bya party required in the ordinary course of its business or by applicable law orregulation.

# **9.             Termination**

## 9.1                                 Term.  Subject only to the provisions of Section 9.2below, the term of this Agreement shall commence upon the Effective Date andterminate on the date on which the last of the Licensed Patents expires (the “Term”).The provisions of Sections 1, 3, 5, 6.2, 7, 8, 9.4, and 11 shall survive anytermination or expiration of this Agreement.

## 9.2           MaterialBreach.

## If a Party:

(a) materially breaches this Agreement in a manner that cannot becured;

## (b) materially breaches this Agreement in amanner that can be cured and such breach remains uncured for thirty (30) daysfollowing written notice of breach by the other Party

                Such breach shall be considered a “Material Breach”.

## 9.3                               Terminationby the Non-Breaching Party.  In theevent of a Material Breach, as defined by Section 9.2, the non-breaching Partymay terminate this Agreement thirty (30) days following written notice to thebreaching Party.

# 9.4                                 Bankruptcy.  All licenses and releases grantedto a Party and its Affiliates under this Agreement are deemed to be, for thepurpose of Section 365(n) of the U.S. Bankruptcy Code, licenses of rights tointellectual property as defined under Section 101 of the U.S. Bankruptcy Code,as amended.  The Parties agree that any Party who is alicensee or beneficiary of such rights under this Agreement, shall retain andmay exercise all of its rights and elections under the U.S. Bankruptcy Code, as amended.  To the extent that similar protections of itsrights are available to the Parties and Affiliates in foreign jurisdictions,the Parties agree that they shall be entitled to retain and exercise all suchrights.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

 

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# **10.          Assignment**

10.1                         Assignment.Neither Party may assign this Agreement or otherwise transfer any of its rightsand interests, nor delegate any of its obligations hereunder, by operation oflaw or otherwise (including pursuant to a merger, recapitalization, shareexchange, consolidation or other transaction), without the prior writtenconsent of the other Party; provided, that AVUK may assign this Agreement as awhole, effective upon written notice to RADVISION, to any entity that acquiresall or substantially all of the assets of AVUK or substantially all of theportions of its business to which this Agreement relates or that is thesurviving entity in a merger, recapitalization, share exchange or consolidationwith AVUK; and provided, further, that AVISTAR may assign its licenseseffective on written notice to RADVISION to any entity that acquires all orsubstantially all of the assets of AVISTAR or substantially all of the portionsof its business to which this Agreement relates or that is the surviving entityin a merger, recapitalization, share exchange or consolidation but in suchevent AVISTAR Licensed Products shall be limited to those AVISTAR LicensedProducts offered for sale by AVISTAR at the date of the assignment and suchproducts then under development by AVISTAR which are offered for sale byAVISTAR or its assignee within eighteen (18) months of the date the assignment and updates, upgrades and naturalextensions of such products and which products in all cases are primarily basedon such products; and provided, further, that RADVISION may assign thisagreement as a whole effective on written notice to AVUK to any entity thatacquires all or substantially all of the assets of RADVISION or substantiallyall of the portions of its business to which this Agreement relates or that isthe surviving entity in a merger, recapitalization, share exchange orconsolidation but in such event RADVISION Licensed Products shall be limited tothose RADVISION Licensed Products offered for sale by RADVISION at the date ofthe assignment and such products then under development by RADVISION which areoffered for sale by RADVISION or its assignee within eighteen (18) months ofthe date the assignment and updates, upgrades and natural extensions of suchproducts and which products in all cases are primarily based on such products.Neither Party may assign this Agreement or otherwise transfer any of its rightsand interests, nor delegate any of its obligations hereunder, by operation oflaw or otherwise to Tandberg. This Agreement shall be binding upon, and inureto the benefit of, the legal representatives, successors and permitted assignsof the Parties. Any attempt to assign or delegate all or any portion of thisAgreement in violation of this Section 10.1 shall be void. Except as otherwiseexpressly provided herein, there shall be no third party beneficiaries, eitherexpress or implied, to this Agreement.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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10.2                           In theevent RADVISION assigns this Agreement in accordance with the provisions ofSection 10.1, the covenant not to sue of Section 3.1 shall extend to theassignee [***] for [***] offered for [***] by [***] at the date of theassignment and such [***] then under development by RADVISION which are offeredfor sale by RADVISION or its assignee within eighteen (18) months of the datethe assignment and updates, upgrades and natural extensions of such [***] whichdo not materially expand the functionality of such [***].

10.3                           EitherParty or its Affiliates (hereafter the Forming Party), at its option and uponwritten notice to the other Party, may [***] or [***] an [***] which will havethe following [***] and be [***] to the following [***].

The [***] shall have:

(a)          A [***] of [***] withinthe [***] of the [***];

(b)         [***] of at least [***];

(c)          [***] including [***];and

(d)         The [***] shall be the[***] of at least [***] or [***] of the [***] or other [***] interest of the[***].

Upon ninety (90) days written request to the otherParty, the other Party will [***] the [***] a [***] upon [***] and [***] of[***] subject to the following:

(a)          The [***] to the [***]will be the [***] and the [***].

(b)         The [***] of the [***] inthe [***] will be consistent with the [***] products and [***] of [***] of the[***] as defined by the [***] and such definition of [***] will be [***] and[***] from the [***] of the [***] under this Agreement; and

(c)          The [***] shall notinclude [***] of [***].

Each Party to this Agreement shall [***] to [***] or [***] during theterm of this Agreement.

# **11.          GeneralProvisions**

## 11.1                           Expensesof the Parties.  Each Party shall payits own expenses incurred in connection with the negotiation, execution andperformance of this Agreement.

## 11.2                           Waiver.  No term or provision hereof will beconsidered waived by either Party, and no breach excused by either Party,unless such waiver or consent is in writing and signed by an authorizedrepresentative on behalf of the Party against whom the waiver is asserted.  No consent by either Party to, or waiver of,a breach by 

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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##                                                 eitherParty, whether express or implied, will constitute a consent to, waiver of, orexcuse of any other different or subsequent breach by either Party.

## 11.3                           Amendmentand Modification.  This Agreement maybe amended, modified and/or supplemented only by means of a written amendment,signed by the authorized representatives of the Parties, which specificallyrefers to this Agreement.

## 11.4                           Notices.  Any notice to any Party hereto given pursuantto this Agreement shall be in writing and given by certified or registeredfirst-class mail, return receipt requested, or by reputable private courierhaving an established tracking capability addressed as follows:

               if to AVUK and AVISTAR:                 AVUK

                                                                BostonHouse

                                                                64-64New Broad Street

                                                                London,UK ECZ M1J

                                                                AVISTAR

                                                                1875South Grant Street

                                                                Suite1000

                                                                SanMateo, CA 94402

                                                                Attention:  Chief Financial Officer

               if to RADVISION:                                 24 RaoulWallenberg Street

                                                                TelAviv, 69719

                                                                Israel

                                                                Attention:General Counsel

A Party may change itsaddress for notice by written notice to the other Party.

## 11.5                           GoverningLaw and Venue.  This Agreement ismade and shall be construed in accordance with and any arbitration underSection 8 will be governed by the laws of the State of New York, without regardto the conflict of laws provisions thereof. This Agreement shall be subject to the exclusive jurisdiction of anyFederal or State court sitting within the geographic boundaries of the SouthernDistrict of New York, and each Party submits to the personal jurisdiction ofany such court and waives any objection it may have to the laying of venuetherein.

## 11. 6                        Headings.  Headings are supplied herein for convenienceonly and shall not be deemed a part of this Agreement for any purpose.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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## 11.7                           Severability.  If any term or provision of this Agreement orthe application thereof to any person or circumstances shall to any extent beinvalid or unenforceable, the remainder of this Agreement or the application ofsuch terms or provisions to persons or circumstances other than those as towhich it is invalid or unenforceable, shall not be affected thereby and eachterm and provision of this Agreement shall be valid and enforceable to thefullest extent permitted by law.

## 11.8                           Confidentiality.  Except as may be required by law orregulations, neither Party shall disclose any of the terms, conditions or otherprovisions of this Agreement without the prior written consent of the otherParty. In the event of such required disclosure, the disclosing Party shallprovide advance notice to the other Party and take all reasonable steps toobtain a protective order or confidential treatment for this Agreement.

## 11.9                           PressRelease. RADVISION and AVISTAR shall make the press release announcementset forth in Exhibit C. CPI may also disclose that RADVISION is a licensee ofthe CPI Licensed Patents without reference to any of the specific terms orconditions of this Agreement,

## 11.10                     ConsequentialDamages.  IN NO EVENT WILL ANY PARTYBE LIABLE FOR LOST PROFITS, OR ANY SPECIAL, INDIRECT, INCIDENTAL ORCONSEQUENTIAL OR EXEMPLARY DAMAGES, HOWEVER CAUSED AND ON ANY THEORY OFLIABILITY, ARISING IN ANY WAY IN CONNECTION WITH THIS AGREEMENT.  THIS LIMITATION WILL APPLY EVEN IF A PARTYHAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES AND NOT WITHSTANDING ANYFAILURE OF ESSENTIAL PURPOSE OF ANY LIMITED REMEDY.

## 11.11                     PartiesAdvised by Counsel. This Agreement has been negotiated between unrelatedParties who are sophisticated and knowledgeable in the matters contained inthis Agreement and who have acted in their own self interest. In addition, eachParty has been represented by legal counsel. This Agreement shall not beinterpreted or construed against any Party to this Agreement because that Partyor any attorney or representative for that Party drafted or participated in thedrafting of this Agreement.

## 11.12                     Compliance.The Parties shall comply with all federal, state and local laws (includingregulations, orders and ordinances) now or hereafter enacted, of anyjurisdiction in which performance occurs or may occur hereunder. Withoutlimitation, each Party hereby acknowledges that the rights and obligations ofthis Agreement are subject to the laws and regulations of the United Statesrelating to the export of products and technical information, and it shallcomply with all such laws and regulations.

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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11.13                     EntireAgreement and Facsimile Execution. This Agreement comprises the entire agreement between the Parties heretoas to the subject matter hereof and supersedes all prior discussions,agreements and understandings, written or oral, between them relatingthereto.  This Agreement may be executedin counterparts and via facsimile and such counterparts shall be treated as anoriginal or when signed, via facsimile, by both Parties; nevertheless, any oneof the Parties may require the follow-up exchange of originals in hardcopy byso requesting in writing within five (5) days of counterpart or facsimileexecution.

INWITNESS WHEREOF, the Parties hereto have caused this Agreement to be signedbelow by their respective duly authorized representatives.
| **RADVISION LTD.**                                                                                                                                                                                                                                                     |       | **AVISTAR SYSTEMS UK LIMITED** |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|--------------------------------|
| ** **                                                                                                                                                                                                                                                             | ** ** |                           |   | ** ** |
| By:                                                                                                                                                                                                                                                                    | [***]      |                           | By: | [***] |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Name:                                                                                                                                                                                                                                                                  | [***]      |                           | Name: | [***] |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Title:                                                                                                                                                                                                                                                                 | [***]      |                           | Title: | [***] |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Date:                                                                                                                                                                                                                                                                  | 6/24/07    |                           | Date: | 6/26/07 |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| By:                                                                                                                                                                                                                                                                    | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Name:                                                                                                                                                                                                                                                                  | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Title:                                                                                                                                                                                                                                                                 | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Date:                                                                                                                                                                                                                                                                  | 6/25/07    |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| **AVISTAR COMMUNICATIONS CORPORATION (Signing to  confirm it is the parent company of CPI and that AVUK has the rights to grant  the licensed to the CPI Licensed Patents to RADVISION and as the recipient of  the patent licenses and other rights from RADVISION)** |
| ** **                                                                                                                                                                                                                                                             | ** ** |                           |   |   |
| By:                                                                                                                                                                                                                                                                    | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Name:                                                                                                                                                                                                                                                                  | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Title:                                                                                                                                                                                                                                                                 | [***]      |                           |   |   |
|                                                                                                                                                                                                                                                                   |       |                           |   |   |
| Date:                                                                                                                                                                                                                                                                  | 6/26/07    |                           |   |   |

 

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

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**AttachmentA**

**CPIPatents**
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   | [***]  |
|-------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   | [***]  |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   | [***]  |   | [***]  |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   | [***]  |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   | [***]  |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |
| [***] |   |   |   |   |   |   |   |   |   |   |   |   |

 

**CPI Applications**

**Published**

(U.S. PublicationApplication Number)
| [***] |   | [***] |   | [***] |   | [***]  |   | [***]  |
|-------|--------|-------|--------|-------|--------|--------|--------|--------|
| [***] |   | [***] |   | [***] |   | [***]  |   | [***]  |
| [***] |   | [***] |   | [***] |   | [***]  |   | [***]  |
| [***] |   | [***] |   | [***] |   | [***]  |   | [***]  |
| [***] |   | [***] |   | [***] |   |   |   |   |

 

**Unpublished**
| (United States) |
|-----------------|
| [***]           |   | [***] |   | [***] |   | [***] |   | [***] |   | [***] |   | [***] |   | [***] |
| [***]           |   | [***] |   | [***] |   | [***] |   | [***] |   |   |   |   |   |   |
|            |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| (Canada)        |
| [***]           |   | [***] |   |   |   |   |   |   |   |   |   |   |   |   |
|            |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| (European)      |
| [***]           |   | [***] |   | [***] |   | [***] |   | [***] |   | [***] |   | [***] |   |   |

 

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portions representedby [***] have been separately filed with the Securities and ExchangeCommission.

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Attachment C

Press Release

[***] Portions of this exhibit have been omitted pursuant to a requestfor confidential treatment filed pursuant to Rule 24-b-2 promulgated under theSecurities Exchange Act of 1934, as amended, and the omitted portionsrepresented by [***] have been separately filed with the Securities andExchange Commission.

17

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