Exhibit 4.8

CAW NETWORKS, INC.

SERIES B PREFERRED STOCK
PURCHASE AGREEMENT

October 16, 2001

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TABLE OF CONTENTS

|   |  |                                                  |  |                                                              |  | Page
|-- |  | ------------------------------------------------ |  | ------------------------------------------------------------ |  | ----
|1. |  | AGREEMENT TO SELL AND PURCHASE                   |  | 1                                                           
|   |  | 1.1                                              |  | Authorization of Shares                                      |  | 1   
|   |  | 1.2                                              |  | Sale and Purchase                                            |  | 1   
|2. |  | CLOSING, DELIVERY AND PAYMENT                    |  | 1                                                           
|   |  | 2.1                                              |  | Closing                                                      |  | 1   
|   |  | 2.2                                              |  | Delivery                                                     |  | 1   
|   |  | 2.3                                              |  | Subsequent Closings                                          |  | 2   
|3. |  | REPRESENTATIONS AND WARRANTIES OF THE COMPANY    |  | 2                                                           
|   |  | 3.1                                              |  | Organization, Good Standing and Qualification                |  | 2   
|   |  | 3.2                                              |  | Subsidiaries                                                 |  | 2   
|   |  | 3.3                                              |  | Capitalization; Voting Rights                                |  | 2   
|   |  | 3.4                                              |  | Valid Issuance of Securities                                 |  | 3   
|   |  | 3.5                                              |  | Authorization; Binding Obligations                           |  | 4   
|   |  | 3.6                                              |  | Financial Statements                                         |  | 4   
|   |  | 3.7                                              |  | Agreements; Action                                           |  | 4   
|   |  | 3.8                                              |  | Obligations to Related Parties                               |  | 5   
|   |  | 3.9                                              |  | Title to Properties and Assets; Liens, Etc.                  |  | 5   
|   |  | 3.10                                             |  | Patents and Trademarks                                       |  | 6   
|   |  | 3.11                                             |  | Compliance with Other Instruments                            |  | 6   
|   |  | 3.12                                             |  | Litigation                                                   |  | 6   
|   |  | 3.13                                             |  | Employees                                                    |  | 7   
|   |  | 3.14                                             |  | Confidential Information and Invention Assignment Agreements |  | 7   
|   |  | 3.15                                             |  | Registration Rights and Voting Rights                        |  | 7   
|   |  | 3.16                                             |  | Compliance with Laws; Permits                                |  | 8   
|   |  | 3.17                                             |  | Offering Valid                                               |  | 8   
|   |  | 3.18                                             |  | Changes                                                      |  | 8   
|   |  | 3.19                                             |  | Employee Benefit Plans                                       |  | 9   
|   |  | 3.20                                             |  | Tax Returns and Payments                                     |  | 9   
|   |  | 3.21                                             |  | Insurance                                                    |  | 10  
|   |  | 3.22                                             |  | Corporate Documents                                          |  | 10  
|   |  | 3.23                                             |  | Real Property Holding Corporation                            |  | 10  
|   |  | 3.24                                             |  | Environmental and Safety Laws                                |  | 10  
|   |  | 3.25                                             |  | Qualified Small Business Stock                               |  | 10  
|   |  | 3.26                                             |  | Disclosure                                                   |  | 10  
|4. |  | REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS |  | 10                                                          
|   |  | 4.1                                              |  | Requisite Power and Authority                                |  | 10  
|   |  | 4.2                                              |  | Investment Representations                                   |  | 11  
|   |  | 4.3                                              |  | Transfer Restrictions                                        |  | 12  
|5. |  | CONDITIONS TO CLOSING                            |  | 12                                                          
|   |  | 5.1                                              |  | Conditions to Purchasers' Obligations at the Closing         |  | 12  
|   |  | 5.2                                              |  | Conditions to Obligations of the Company                     |  | 13  
|6. |  | MISCELLANEOUS                                    |  | 14                                                          
|   |  | 6.1                                              |  | Governing Law                                                |  | 14  
|   |  | 6.2                                              |  | Survival                                                     |  | 14  
|   |  | 6.3                                              |  | Successors and Assigns                                       |  | 14  
|   |  | 6.4                                              |  | Entire Agreement                                             |  | 14  
|   |  | 6.5                                              |  | Severability                                                 |  | 14  
|   |  |                                                  |  |                                                              |  |     

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| |  | 6.6  |  | Amendment and Waiver                |  | 14
| |  | ---- |  | ----------------------------------- |  | --
| |  | 6.7  |  | Delays or Omissions                 |  | 15
| |  | 6.8  |  | Waiver of Conflicts                 |  | 16
| |  | 6.9  |  | Notices                             |  | 16
| |  | 6.10 |  | Expenses                            |  | 16
| |  | 6.11 |  | Attorneys' Fees                     |  | 16
| |  | 6.12 |  | Titles and Subtitles                |  | 16
| |  | 6.13 |  | Counterparts                        |  | 16
| |  | 6.14 |  | Broker's Fees                       |  | 16
| |  | 6.15 |  | Exculpation Among Purchasers        |  | 17
| |  | 6.16 |  | Confidentiality                     |  | 17
| |  | 6.17 |  | Pronouns                            |  | 17
| |  | 6.18 |  | California Corporate Securities Law |  | 17

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LIST OF EXHIBITS

|Schedule of Purchasers                                              |  | Exhibit A
|------------------------------------------------------------------- |  | ---------
|Restated Certificate                                                |  | Exhibit B
|Amended and Restated Investor Rights Agreement                      |  | Exhibit C
|Amended and Restated Voting Agreement                               |  | Exhibit D
|Amended and Restated Co-Sale Agreement                              |  | Exhibit E
|Form of Legal Opinion                                               |  | Exhibit F
|Form of Confidential Information and Invention Assignment Agreement |  | Exhibit G

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CAW NETWORKS, INC.

SERIES B PREFERRED STOCK PURCHASE AGREEMENT

THIS SERIES B PREFERRED STOCK PURCHASE AGREEMENT(the
"Agreement") is entered into as of October 16, 2001, by and amongCAW NETWORKS, INC., a Delaware
corporation (the "Company"), and each of those persons and entities, severally and not jointly, whose names are set forth on the Schedule of Purchasers
attached hereto asExhibit A(which persons and entities are hereinafter collectively referred to as
"Purchasers" and each individually as a "Purchaser").

Recitals

WHEREAS,the Company has authorized the sale and issuance of an aggregate of Eight Million Five Hundred
Forty-Five Thousand Four Hundred Fifty-Five (8,545,455) shares of its Series B Preferred Stock (the "Shares");

WHEREAS,Purchasers desire to purchase the Shares on the terms and conditions set forth herein; and

WHEREAS,the Company desires to issue and sell the Shares to Purchasers on the terms and conditions set forth herein;

NOW, THEREFORE,in consideration of the foregoing recitals and the mutual promises hereinafter set forth, the parties hereto agree as
follows:

1.    AGREEMENT TO SELL AND PURCHASE.



2.    Closing, Delivery and Payment.



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3.    REPRESENTATIONS AND WARRANTIES OF THE COMPANY.

Except
as set forth on a Schedule of Exceptions delivered by the Company to the Purchasers at the Closing, the Company hereby represents and warrants to each Purchaser as of the date of
this Agreement as follows:



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4.    REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS.

Each
Purchaser hereby represents and warrants to the Company as follows (such representations and warranties do not lessen or obviate the representations and warranties of the Company
set forth in this Agreement):



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5.    CONDITIONS TO CLOSING.



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6.    MISCELLANEOUS.



6.6    Amendment and Waiver.



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IN WITNESS WHEREOF, the parties hereto have executed theSeries B Preferred Stock Purchase
Agreementas of the date set forth in the first paragraph hereof.

| |  | COMPANY:          
| |  | ------------------
| |  | CAW NETWORKS, INC.
| |  | By:               
| |  | Address:          

SIGNATURE PAGE TO SERIES B
PREFERRED STOCK PURCHASE AGREEMENT

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IN WITNESS WHEREOF, the parties hereto have executed theSERIES B PREFERRED STOCK PURCHASE
AGREEMENTas of the date set forth in the first paragraph hereof.

| |  | PURCHASER:                  
| |  | ----------------------------
| |  | Spirent Holdings Corporation
| |  | By:                         
| |  | Name:                       
| |  | Title:                      
| |  | Address:                    

SIGNATURE PAGE TO SERIES B
PREFERRED STOCK PURCHASE AGREEMENT

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IN WITNESS WHEREOF, the parties hereto have executed theSERIES B PREFERRED STOCK PURCHASE
AGREEMENTas of the date set forth in the first paragraph hereof.

| |  | PURCHASERS:                                                                           
| |  | --------------------------------------------------------------------------------------
| |  | MENLO VENTURES VIII, L.P.
BY: MV MANAGEMENT VIII, L.L.C.
Its General Partner          
| |  | By:                                                                                   
| |  | MENLO ENTREPRENEURS FUND VIII, L.P.
BY: MV MANAGEMENT VIII, L.L.C.
Its General Partner
| |  | By:                                                                                   
| |  | MMEF VIII, L.P.
BY: MV MANAGEMENT VIII, L.L.C.
Its General Partner                    
| |  | By:                                                                                   
| |  | Address:                                                                              

SIGNATURE PAGE TO SERIES B
PREFERRED STOCK PURCHASE AGREEMENT

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AGREEMENT AND PLAN OF MERGER

AGREEMENT
AND PLAN OF MERGER, dated as of July 21, 2002, among Spirent plc, a company organized under the laws of England and Wales
("Parent"), Spirent Holdings Corporation, a Delaware corporation ("SHC") and an indirect, wholly-owned
subsidiary of Parent, Cancun Acquisition Corp., a Delaware corporation and a wholly-owned, direct subsidiary of SHC ("Merger Sub") and Caw
Networks, Inc., a Delaware corporation (the "Company"). Capitalized terms used in this Agreement without definition are defined in ARTICLE VIII.

RECITALS

WHEREAS, the respective boards of directors of each of Parent, SHC, Merger Sub and the Company have determined that it is in the best interests of each of their
respective companies and stockholders for Merger Sub to be merged with and into the Company, on the terms and subject to the conditions of this Agreement (the
"Merger");

WHEREAS,
SHC is currently the record holder of 5,515,152 shares of Series B Preferred Stock of the Company (such shares, the "SHC Preferred
Stock");

WHEREAS,
as a result of the Merger, all issued and outstanding shares of, and warrants to purchase, capital stock of the Company (other than the SHC Preferred Stock) shall be converted
into the right to receive the applicable Merger Consideration, and all options to acquire shares of the capital stock of the Company shall be converted into options to purchase shares of the capital
stock of Parent, each on the terms and subject to the conditions set forth herein; and

WHEREAS,
Parent's willingness to enter into this Agreement and to consummate the Merger is conditioned upon the execution and delivery of the Pre-Merger Agreement of
Stockholders on the date hereof by Stockholders holding a majority of the issued and outstanding shares of Series A Preferred Stock and Series B Preferred Stock, voting together as a
class, and a majority of the outstanding stock of the Company entitled to vote on the adoption of this Agreement.

NOW,
THEREFORE, the Parties agree as follows:

ARTICLE I

The Merger

1.1.The Merger.



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1.2.Conversion of Stock.At the Effective Time, by virtue of the Merger and without any further action on the
part of the holder of any securities of the Company, Merger Sub, Parent or any other Person:



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1.3.Treatment of Options.



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1.4.Closing; Effective Time.



1.5.Escrow Arrangements; Repayment of Indebtedness to Company.



1.6.Exchange of Certificates.



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1.7.Legends; Restrictions.



The
Parent Ordinary Shares issued pursuant to Section 1.2(a)(ii) will also bear the following legend:



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1.8.Shares of Dissenting Stockholders.



1.9.Earn-Out.



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1.10.Actions With Respect to Non-Accredited Investors.If Parent, SHC and Merger Sub shall have not
received questionnaires (or other evidence satisfactory to Parent) sufficient to satisfy the condition set forth in Section 6.2.12 within ten days following the date of this Agreement (and in
any event prior to the mailing to Stockholders of any of the Notice to Stockholders, the Information Statement or the letter of transmittal referred to in Section 1.6), either
(a) the Company shall cause such condition to be met by procuring the purchase of shares of capital stock of the Company held by certain Stockholders
who are not accredited investors, or (b) Parent shall be entitled to designate certain Stockholders who are not accredited investors (as Parent may
determine in consultation with the Company) as not eligible to receive Parent Ordinary Shares. Any Stockholder so designated will receive, in lieu of Parent Ordinary Shares, cash of equivalent value
determined in accordance with the principles set forth in Sections 1.2(a)(ii) or 1.9, as applicable.

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ARTICLE II

Representations and Warranties of the Company

The Company represents and warrants to Parent, SHC and Merger Sub, as of the date of this Agreement and as of the Closing Date, that the statements set forth in
this Article II are true and correct, except as expressly set forth in the disclosure schedules attached to this Agreement (the "Company Disclosure
Schedules"). The Company Disclosure Schedules shall be arranged in paragraphs corresponding to the numbered and lettered paragraphs contained in this Article II and
shall be deemed to cross reference to the other numbered or lettered paragraphs to which the representation and warranty with respect to which disclosure is made reasonably relates on the face of such
disclosure without reference to extrinsic documentation. Moreover, disclosures made on the Company Disclosure Schedules shall not, by virtue of their disclosure, be deemed to be an acknowledgment that
disclosure of such information is required under this Article II:

2.1.Authorization, etc.



2.2.Stockholders; Capitalization, etc.



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2.3.No Conflicts, etc.The Company's execution, delivery and performance of this Agreement and the other
Transaction Agreements to which it is a party, and their consummation of the transactions contemplated by them, do not and will not conflict with, contravene, result in a violation or breach of or
default under (with or without the giving of notice or the lapse of time or both), create in any other Person a right or claim of termination, amendment, or require modification, acceleration or
cancellation of, or result in the creation of a Lien (or any obligation to create a Lien) on any of the Company's properties or assets under:



2.4.Corporate Status.



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2.5.European Union Operations.Except as stated in Schedule 2.5, the Company does not have any
operations or assets in the United Kingdom or the European Union, or derive any revenues or income from the United Kingdom or the European Union.

2.6.Financial Statements.



2.7.Undisclosed Liabilities, etc.The Company does not have any liabilities or obligations of any nature,
whether known, unknown, absolute, accrued, contingent or otherwise and whether due or to become due, except:



Since
December 31, 2001, there has not occurred or come to exist any Material Adverse Effect or any event, occurrence, fact, condition, change, development or effect that, individually or in
the aggregate, would be reasonably likely to become or result in a Material Adverse Effect.

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2.8.Absence of Changes.Since December 31, 2001, except
(a) as stated in Schedule 2.8 and (b) as specifically permitted after the date of this Agreement
under Section 4.1, the Company has carried on its Business in the ordinary course of business, in substantially the same manner as conducted before that date, and has not:



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2.9.Tax Matters.



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2.10.Assets.



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2.11.Real Property.



2.12.Contracts.



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2.13.Intellectual Property.



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2.14.Insurance.



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2.15.Litigation.

Except
as stated in Schedule 2.15, there is not currently, and never has been any Litigation pending, withdrawn, settled or, to the Company's knowledge, threatened against the
Company or its properties or assets. There are no outstanding orders, rulings, decrees, judgments, stipulations or injunctions issued by any Governmental Authority against the Company, or, to the
Company's knowledge, that materially affect the Business.

2.16.Compliance with Laws and Instruments; Consents.





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2.17.Environmental Matters.Except as disclosed on Schedule 2.17:



2.18.Affiliate Transactions.





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2.19.Employees, Labor Matters, etc.



2.20.Employee Benefit Plans and Related Matters; ERISA.



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2.21.Immigration.The Company has complied in all material respects with all applicable U.S. immigration laws
to which it is subject. Without limiting the generality of the foregoing, Forms I-9 have been properly completed for all current and former employees of the Company pursuant to the
Immigration Reform and Control Act and the regulations thereunder, and the Company has complied with all Forms I-9 record keeping requirements thereunder. The Forms H-1 and TN
and all labor certifications filed by the Company with the Immigration and Naturalization Service ("INS") and Department of Labor
("DOL"), respectively, are true and correct in all material respects, and the Company has not been the subject of any audit or investigation by the INS
or DOL with respect thereto.

2.22.Accounts Receivable.Except as stated in Schedule 2.22, all accounts receivable reflected on, as of
the date of this Agreement, the most recent balance sheet in the Financial Statements and, as of the Closing Date, the most recently delivered balance sheet under Section 4.5:



All
allowances, rebates and cash discounts to the Company's customers are as shown on its books and records and in no event exceed one percent of receivables to which they relate.

2.23.Inventories.To the Company's knowledge, all of its inventories of raw materials and supplies, and all of
its inventories of work in progress and finished goods are of good and, usable quality and, except as stated in Schedule 2.23:



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2.24.Customers; Sales Representatives.



2.25.Suppliers; Raw Materials.No goods or services that are material to the Company are supplied to the
Company solely by a single supplier that, if such supply relationship were terminated, could not, to the Company's knowledge, be replaced immediately by an alternate supplier on reasonable terms and
conditions.

2.26.Products; Product and Service Warranties.



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2.27.Bank Accounts.Schedule 2.27 lists each bank in which the Company has an account or safe deposit or
lock box, the account or box number, as the case may be, and the name of every Person authorized to draw on it or having access to it.

2.28.Exon-Florio.The nature the Business will not cause the acquisition of the Company by Parent
to be subject to the Exon-Florio Amendment (Section 721 of Title VII of the Defense Protection Act of 1950).

2.29.Brokers, Finders, etc.Except for a fee payable by the Company immediately prior to the Effective Time to
Schroders Salomon Smith Barney, all negotiations relating to the Transaction Agreements and the transactions contemplated by them have been carried on without the participation of any Person acting on
behalf of the Company or, to the Company's knowledge, any Stockholder in such a manner as to, and the transactions contemplated by them will not otherwise, give rise to any valid claim against the
Company, Parent, Merger Sub or the Surviving Corporation or any of their Affiliates for any brokerage or finder's commission, fee or similar compensation, or for any bonus payable to any officer,
director, employee, agent or representative of or consultant to the Company on consummation of the transactions contemplated by them.

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2.30.Disclosure.



ARTICLE III

Parent's, SHC's and Merger Sub's Representations and Warranties

Parent, SHC and Merger Sub, jointly and severally, represent and warrant to the Company, as of the date of this Agreement and as of the Closing Date, as follows:

3.1.Corporate Status; Authorization, etc.Each of Parent, SHC and Merger Sub is a corporation duly
incorporated, validly existing and in good standing under the laws of its jurisdiction of incorporation. Each of Parent, SHC and Merger Sub has full corporate power and authority to execute and
deliver this Agreement and the other Transaction Agreements to which it will be a party, to perform its obligations under them and to consummate the transactions contemplated by them. Each of Parent,
SHC and Merger Sub has duly authorized its execution and delivery of this Agreement and the other Transaction Agreements to which it will be a party, the performance of its obligations under them, and
the consummation of the transactions contemplated by them. Each of Parent, SHC and Merger Sub has duly executed and delivered this Agreement, and as of the Closing Date will have duly executed and
delivered the other Transaction Agreements to which it will be a party. This Agreement constitutes, and each such other Transaction Agreement when so executed and delivered will constitute, the legal,
valid and binding obligation of Parent, SHC and Merger Sub, enforceable against Parent, SHC and Merger Sub in accordance with its terms.

3.2.No Conflicts, etc.



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3.3.Accuracy of Information.Parent's 20-F filed with the Securities and Exchange Commission on
May 17, 2002 does not as of the date of filing, contain any untrue statement of material fact or omit to state a material fact required to be stated therein or needed to make the statements
contained therein not misleading.

3.4.Brokers, Finders, etc.All negotiations relating to the Transaction Agreements and the transactions
contemplated by them have been carried on without the participation of any Person acting on behalf of Parent, SHC or Merger Sub in such a manner as to, and the transactions contemplated the
Transaction Agreements will not otherwise, give rise to any valid claim against the Company or any of its Affiliates for any brokerage or finder's commission, fee or similar compensation.

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3.5.Resalability of Parent Ordinary Shares.



ARTICLE IV

The Company's Covenants

4.1.Conduct of Business.From the date of this Agreement until the Closing Date, except as expressly required
by this Agreement or with Parent's prior express written consent, which may be granted or withheld by Parent in its sole but good faith discretion, the Company will:



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4.2.No Solicitation.During the term of this Agreement, the Company will not, and will cause its Affiliates and
Representatives not to:



The
Company will promptly notify Parent of any inquiry or proposal it or its Affiliates or Representatives receive relating to an Acquisition Transaction. The Company will immediately cease and cause
to be terminated any existing activities, discussions or negotiations with any Person other than Parent in respect of an Acquisition Transaction.

4.3.Materials Delivered to Stockholders.



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4.4.Access and Information.So long as this Agreement remains in effect, the Company will (and will cause its
Representatives to):



4.5.Subsequent Financial Statements and Reports; Review Report.From the date of this Agreement until the
Effective Time, commencing with the month ended June 30, 2002, the Company will:



4.6.Public Announcements.Except as required by Law, the Company will not, and will not permit any of its
Affiliates or Representatives to, make any public announcement about a Transaction Agreement or the transactions contemplated by a Transaction Agreement without Parent's prior written consent
(including consent as to the form and wording of the announcement).

4.7.Further Actions.



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4.8.No Dealing in Parent Ordinary Shares.Until the earlier of
(a) the Closing and (b) the termination of this Agreement under Article VII, the Company will
not, and will use commercially reasonable efforts to cause the Company's employees, officers and directors not to, acquire or otherwise deal in any securities of Parent, including Parent Ordinary
Shares, without Parent's written consent.

4.9.Certificate of Chief Financial Officer.The Company will provide Parent with a certificate of its Chief
Financial Officer on the date that is five Business Days prior to the Closing Date, certifying (a) the aggregate amount of cash used and to be used by
the Company prior to or at the Effective Time for the payment of Seller Transaction Expenses, (b) the principal amount of, and the amount of accrued but
unpaid interest on, any Indebtedness of the Company to be outstanding as of the Effective Time. Such certificate shall be accompanied by such appropriate documentation as may be reasonably requested
by Parent, including, without limitation, receipts, invoices (including, without limitation, final invoices from legal, financial or auditing advisors to the Company or the Stockholders covering all
work that is to be borne by the Company or the Stockholders pursuant to Section 9.1) and other statements by service providers.

ARTICLE V

Parent's, SHC's and Merger Sub's Covenants

5.1.Public Announcements.Before the Closing, except as required by Law or the rules of the London Stock
Exchange, the New York Stock Exchange or the Listing Rules of the UK Listing Authority, Parent will not, and will not permit any of its Affiliates to, make any public announcement about the
Transaction Agreements or the transactions contemplated by them without the Company's prior written consent (including consent as to the form and wording of the announcement).

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5.2.Further Actions.



5.3.Employee Benefits Matters.



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5.4.Operation of the Surviving Corporation.During the Earn-Out Period, Parent and SHC will operate
the business of the Surviving Corporation in accordance with the principles set forth on Schedule 5.4, provided that Parent and SHC will not be deemed to have failed to perform this covenant
for the purposes of the indemnification provisions set forth in the Pre-Merger Agreement of Stockholders or the Post-Merger Agreement of Stockholders unless Parent fails to
remedy a breach and the parties fail to agree on an appropriate reduction in the Qualifying Revenues targets (as such term is used in Schedule 5.4), in either case within the time periods
specified in Schedule 5.4.

ARTICLE VI

Conditions Precedent

6.1.Conditions to Obligations of Each party.The Company's, Parent's, SHC's and Merger Sub's obligations to
consummate the transactions contemplated by this Agreement are subject to the fulfillment at or before the Closing Date of the following conditions:



6.2.Conditions to Obligations of Parent, SHC and Merger Sub.Parent's, SHC's and Merger Sub's obligations to
consummate the transactions contemplated by this Agreement are subject to the fulfillment at or before the Closing Date of the following additional conditions:



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6.3.Conditions to Obligations of the Company.The Company's obligations to consummate the transactions
contemplated by this Agreement will be subject to the fulfillment, on or before the Closing Date, of the following additional conditions:



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ARTICLE VII

Termination

7.1.Termination.This Agreement may be terminated prior to the Effective Time:



7.2.Effect of Termination.



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ARTICLE VIII

Definitions

8.1.Terms Generally.In this Agreement:



8.2.Certain Terms.Whenever used in this Agreement, capitalized terms have the meanings given to them as set
forth below, unless the context otherwise requires.

Acquisition Transaction:defined in Section 4.2(i).

Affiliate:of a Person means a Person that directly or indirectly through one or more intermediaries controls, is controlled
by, or is under common control with, the first Person. "Control" means having, directly or indirectly, the power to direct or cause the direction of a
Person's policies, whether through owning voting securities, by contract or credit arrangement, as trustee or executor, or otherwise and "controlled by" and "under common control with" have
corresponding meanings).

Aggregate Market Value:the applicable number of Parent Ordinary Shares, multiplied by the Market Price.

Agreement:this Merger Agreement, including its Exhibits and Schedules.

Appraisal Rights:rights of Dissenting Stockholders to the proposed Merger, including rights of appraisal under the DGCL, the
California Statute and the Company's Certificate of Incorporation and By-Laws.

Assets:defined in Section 2.10(a).

Business:the Company's business and operations as currently conducted or as currently contemplated by the Company to be
conducted prior to giving effect to the transactions contemplated hereby.

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Business Day:a day, other than a Saturday or a Sunday, when banks in London and New York are lawfully open for business.

California Statute:defined in 1.8.

Certificates:defined in Section 1.6.

Certificate of Merger:defined in Section 1.4(b).

Closing:defined in Section 1.4(a).

Closing Date:defined in Section 1.4.

Code:the Internal Revenue Code of 1986, as amended.

Commercial Agreement:the Technology, Development and Reselling Agreement, between Spirent Communications, Inc. and
the Company, dated October 26, 2001.

Commercial Software:defined in Section 2.13(h).

Common Stock:defined in Section 1.2(a)(i).

Common Stock Closing Amount:means cash (in U.S. Dollars) equal to the quotient obtained by dividing
(x) (i) $49 million minus (ii) the amount of
Seller Transaction Expenses paid by the Company prior to or at the Effective Time other than Seller Transaction Expenses for which the Company is responsible pursuant to Section 9.1(a)(ii), and
(iii) the principal amount of, and the amount of any accrued but unpaid interest on, any Indebtedness of the Company outstanding as of the Effective
Time, in excess of the outstanding amount under the Epic Lease as of the Effective Time (not to exceed $280,000) by (y) the number of Fully Diluted
Shares as of the Effective Time.

Common Stock Earn-Out Amount:defined in Section 1.9(e).

Common Stock Merger Consideration:defined in Section 1.2(a)(i).

Company:defined in the first paragraph of this Agreement.

Company Intellectual Property:defined in Section 2.13(c).

Company's knowledge:the actual knowledge of any of the Company's officers or directors, along with Trevor Binns, after
reasonable inquiry of the Company employees having responsibility for the relevant matter.

Confidentiality Agreement:defined in Section 9.2.

Consent:a consent, approval, authorization, waiver, permit, grant, franchise, concession, agreement, license, certificate,
exemption, order, registration, declaration, filing, report or notice of, with or to any Person.

Contract:defined in Section 2.12(a)

DGCL:the Delaware General Corporation Law.

Deferred Consideration:defined in Section 1.2(a)(ii)(A).

Dispute Notice:defined in Section 1.9(c)(iii).

Dissenting Stockholder:defined in Section 1.8(a).

Dissenting Shares:defined in Section 1.8(a).

47

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Early Exercise Restricted Stock:Common Stock that is held by a Restricted Stockholder as of the Effective Date and is
subject to a Repurchase Right pursuant to the early exercise of an unvested Option granted to the Restricted Stockholder under the Company's 2000 Stock Plan.

Earn-Out Amounts:defined in Section 1.9(e).

Earn-Out Period:defined in Section 1.9(b)(i).

Earn-Out Date:defined in Section 1.9(c)(v).

Earn-Out Value:for any number of Parent Ordinary Shares, such number of Parent Ordinary Shares multiplied by
£1.20 (as proportionately adjusted for stock splits, reverse splits, and the like), converted to U.S. Dollars using the Exchange Rate.

Effective Price:the greater of (x) the average daily closing
mid-market price of a Parent Ordinary Share as published in the UK Listing Authority's Daily Official List during the 10 Business Day period ending on the Business Day that is one Business
Day before the Closing and (y) £1.20 (as appropriately adjusted for stock splits, reverse splits, and the like).

Effective Time:defined in Section 1.4(b).

Employees:Defined in Section 2.20(a).

Employment Agreement:an employment and severance agreement substantially in the form of Exhibit E.

Environmental Law:any foreign, federal, state or local law, statute, regulation, rule, order, ordinance, decree, injunction,
judgment, governmental approval or any other requirement of law (including common law) regulating or relating to the protection of human health or safety, natural resources or the environment,
including, but not limited to, laws relating to pollution, contamination or the use, generation, management, handling, transport, treatment, disposal, storage, release or threatened release of
Hazardous Substances.

Epic Lease:shall mean the Equipment Finance Agreement No. 1122-01 between the Company and Epic Funding
Corporation, undated, Equipment Finance Agreement No. 1122-02 between the Company and Epic Funding Corporation, dated November 31, 2000, and Equipment Finance Agreement
No. 1122-03 between the Company and Epic Funding Corporation dated January 12, 2001.



48

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ERISA:the Employee Retirement Income Security Act of 1974, as amended.

Escrow Agent:The Bank of New York, or such other agent as determined in accordance with the Escrow Agreement.

Escrow Amount:$5,000,000.

Escrow Agreement:the Escrow Agreement among the Stockholders, the Stockholders' Agents, Parent and the Escrow Agent (as
defined in the Escrow Agreement) substantially in the form of Exhibit F.

Exchange Rate:the average £/US$ daily closing mid-price exchange rate, as published in The Financial
Times over the 10 Business Days ending on the Business Day that is one Business Day before the Closing Date or Earn-Out Date, as applicable (not counting the Closing Date or
Earn-Out Date, as the case may be, itself).

Expenses:the expenses, costs and fees (including attorneys', auditors' and financial advisors' fees) incurred in connection
with the transactions contemplated by the Transaction Agreements.

Financial Statements:the Company's consolidated financial statements as of and for the period from November 17, 1999
to December 31, 2000 and for the fiscal year ended December 31, 2001 (together with reports on those year-end statements by PricewaterhouseCoopers), including in each case a
balance sheet, a statement of operations, a statement of changes in mandatorily redeemable convertible preferred stock and stockholders' deficit, and a statement of cash flows, and accompanying notes
and monthly management financial reports for the months ended January 31, February 28, March 31, April 30 and May 31, 2002.

Fully Diluted Shares:the aggregate number of (i) shares of Common Stock
issued and outstanding (other than any shares of Common Stock held in the Company's treasury), (ii) shares of Common Stock into which each issued and
outstanding share of Non-SHC Preferred Stock is convertible as of the Effective Time, (iii) shares of Common Stock into which each issued
and outstanding Option is exercisable as of the Effective Time (regardless of vesting schedules) and (iv) shares of Common Stock issuable upon the
conversion of the maximum number of shares of Preferred Stock into which any warrants issued by the Company are exercisable as of the Effective Time.

Governmental Approval:any Consent of, with or to any Governmental Authority.

49

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Governmental Authority:(i) a nation or government, or state or other political subdivision of a nation or
government;



Hazardous Substances:means any substance, material, chemical, compound, product, pollutant or contaminant that:
(i) is or contains asbestos, urea formaldehyde foam insulation, polychlorinated biphenyls, petroleum, petroleum products or petroleum-derived substances
or wastes, radon gas or related materials (ii) requires remedial action under any Environmental Law, or is defined, listed or identified as a "hazardous
waste," "hazardous substance" or words of similar import thereunder, or (iii) is toxic, explosive, corrosive, flammable, infectious, radioactive,
carcinogenic, mutagenic, or otherwise hazardous and is regulated under any Environmental Law, excluding common, properly maintained office and janitorial supplies.

HSR Act:the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and the rules and regulations
under it.

Income Tax:any Taxes computed in whole or in part based on or by reference to net income, capital, net worth or profit and
any franchise, alternative, minimum, accumulated earnings or personal holdings company Tax (including related interest penalties and additions).

Indebtedness:as applied to any Person, means, without duplication:



Information Statement:defined in Section 4.3(a)(ii).

Integrated Revenues:the actual revenues in respect of the Qualifying Products and Services, of Parent and its subsidiaries,
recognized in accordance with U.S. GAAP and consistent with Parent's accounting policies and measured in U.S. dollars (based on prevailing exchange rates at the time of sale(if necessary)), excluding
intra-group revenues and after deduction of any discounts, returns or credit notes issued.

Intellectual Property:defined in Section 2.13(a).

IRS:the Internal Revenue Service.

50

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Key Employees:Andrew Foss, Dana Granoski, Michael Stevens, Douglas Bergh, John Kenney, Roy Chua, Philip Joung, Roland
Hendel, John Blakkan and Andrew Pearce.

Law:the applicable provisions of:



Leases:the real property leases, subleases, licenses and occupancy agreements under which the Company is the lessee,
sublessee, licensee, user or occupant of real property used in or held for use in connection with, necessary for the conduct of, or otherwise material to, the Business.

Lien:a mortgage, pledge, deed of trust, hypothecation, right of others, claim, security interest, encumbrance, burden, title
defect, title retention agreement, lease, sublease, license, occupancy agreement, easement, covenant, condition, encroachment, voting trust agreement, interest, option, right of first offer,
negotiation or refusal, proxy, lien, charge or other restrictions or limitations of any nature whatsoever, including those arising under a Contract.

Litigation:an action, cause of action, claim, demand, suit, proceeding, citation, summons, subpoena, inquiry or
investigation of any nature, civil, criminal, regulatory or otherwise, in law or in equity, by or before any court, tribunal, arbitrator or other Governmental Authority.

London Stock Exchange:London Stock Exchange plc.

Market Price:the average daily closing mid-market price of a Parent Ordinary Share as published in the UK
Listing Authority's Daily Official List during the 10 Business Day period ending on the Business Day that is one Business Day before the Closing Date or the Earn Out Date, as the case may be.

Material Adverse Effect:(i) an event, occurrence, fact, condition, change, development or effect that is or is
reasonably likely to be materially adverse to the Company's Business, operations, results of operations, condition (financial or otherwise), properties (including intangible properties), assets
(including intangible assets) or liabilities; or



Material Respects:"all Material Respects" means:



Merger:defined in the first Recital of this Agreement.

Merger Consideration:the Common Stock Merger Consideration, the Parent Ordinary Shares and cash, if any, issued pursuant to
Section 1.2(a)(ii), the Non-SHC Preferred Stock Merger Consideration, and the New Options issued pursuant to Section 1.3.

Merger Sub:defined in the first paragraph of this Agreement.

New Option:defined in Section 1.3.

51

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New Restricted Stock:defined in Section1.2(a)(ii)(B).

Non-Competition Agreement:a non-competition agreement substantially in the form of Exhibit H.

Non-SHC Preferred Stock:each share of Preferred Stock other than the shares of SHC Preferred Stock.

Non-SHC Preferred Stock Earn-Out Account:defined in Section 1.9(e).

Non-SHC Preferred Stock Merger Consideration:defined in Section 1.2(b)(i).

Notice to Stockholders:defined in Section 4.3(a)(i).

Official List:The official list maintained by the UK Listing Authority.

Old Restricted Stock:Common Stock that was initially granted to a Restricted Stockholder pursuant to a restricted stock
purchase agreement, common stock purchase agreement or stock purchase right and which is held by the Restricted Stockholder as of the Effective Date and is subject to a Repurchase Right.

Option:defined in Section 1.3.

Option Earn-Out Amount:defined in Section 1.9(e).

Organizational Documents:certificate or articles of incorporation, certificates of designations and by-laws.

Owned Intellectual Property:defined in Section 2.13(b).

Owned Software:defined in Section 2.13(h).

Parent:defined in the first paragraph of this Agreement.

Parent Group:defined in 6.3.2.

Parent Material Adverse Effect:defined in 6.3.2.

Parent Ordinary Share:an ordinary share, par value £0.033, of Parent.

Permitted Liens:(i) Liens reserved against in the 2001 Balance Sheet (to the extent so reserved);



Permitted Repurchases:defined in Section 4.1(vii).

Person:a natural person, firm, partnership, association, corporation, company, trust, business trust, Governmental Authority
or other entity.

Plans:defined in Section 2.20(a).

Post-Merger Agreements of Stockholders:the agreements to be entered into among Parent, SHC and each Stockholder
that is not a party to the Pre-Merger Agreement of Stockholders, each to be substantially in the form of Exhibit K hereto.

Preferred Stock:means the Series A Preferred Stock and the Series B Preferred Stock.

52

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Pre-Merger Agreement of Stockholders:the Pre-Merger Agreement of Stockholders, dated as of the date
hereof, among Parent, Merger Sub and the Stockholders party thereto.

Prime Rate:the interest rate publicly announced by Citibank N.A. from time to time in New York City as its prime rate.

Products:defined in Section 2.26(a).

Pro Rata Basis:a proportionate amount based on ownership of Common Stock, assuming, as applicable,
(i) the exercise in full of any warrants to purchase capital stock of the Company, (ii) the conversion
into Common Stock of all shares of Non-SHC Preferred Stock, including the shares of Series A Preferred Stock into which any warrants are exercisable and
(iii) the exercise of all Options (regardless of vesting schedules), each immediately prior to the Effective Time.

Qualifying Products and Services:the following products and services: (i)
the standalone WebReflector and WebAvalanche products of the Company at the date hereof, including any developments thereof; (ii) the Spirent TeraCaw
product, including any development thereof; (iii) Spirent SMB 6000 chassis sold where such chassis are sold at the same time as, and specifically for
use with, Spirent TeraCaw product; (iv) future Parent products which utilize technology owned by the Company at the date hereof;
(v) Spirent software applications where such applications are sold at the same time as, and specifically for use with, Spirent TeraCaw product;
(vi) future Parent products developed by, or in conjunction with, individuals employed by the Company at the date hereof, as agreed in writing by Parent
and the Stockholders' Agents from time to time; and (vii) maintenance contracts and professional service arrangements provided in connection with the
above.

Real Property:interests leased under the Leases, together with the real property that the Company operates or occupies on
the date of this Agreement or at the Effective Time (including the structures, facilities, improvements, fixtures, systems, equipment and items of property located on, attached to or appurtenant to
that real property) and related easements, licenses, rights and appurtenances.

Related Persons:defined in Section 2.20(a).

Representatives:as to any Person, its accountants, counsel, consultants (including actuarial, environmental and industry
consultants), officers, directors, employees, agents and other advisors and representatives.

Repurchase Right:the right of the Company to repurchase shares of Restricted Stock held by a Restricted Stockholder at the
original cost to the Restricted Stockholder in the event that such Restricted Stockholder's termination of employment occurs prior to the vesting date(s) of such shares of Restricted Stock.

Restricted Consideration:defined in Section 1.2(a)(ii)(B).

Restricted Stock:Common Stock of the Company that is either Old Restricted Stock or Early Exercise Restricted Stock.

Restricted Stockholder:an Employee of the Company who holds Restricted Stock.

Sales Representatives:defined in Section 2.24(c)(i).

Securities Act:the Securities Act of 1933, and the rules and regulations promulgated under it.

Seller Transaction Expenses:defined in Section 9.1(a)(ii).

53

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Series A Preferred Stock:the Series A Preferred Stock of the Company, par value $.0001 per share.

Series B Preferred Stock:the Series B Preferred Stock of the Company, par value $.0001 per share.

Shares:shares of Common Stock and shares of Preferred Stock.

SHC:defined in the first paragraph of this Agreement.

SHC Preferred Stock:defined in the Recitals to this Agreement.

Software:all computer software and databases, including application software and system software, including all source code
and object code versions, in any and all forms and media, whether recorded on paper, magnetic media or other electronic or non-electronic media (including data and related documentation,
user manuals, training materials, flow charts, diagrams, descriptive tests and programs, computer print-outs, underlying tapes and similar items), integrated circuits, embedded systems,
and other electro-mechanical or processor based systems.

Stockholders:each holder of Shares identified on Schedule 2.2(a) and any other Person who becomes a holder of Shares
in the period from the date of this Agreement until immediately before the Effective Time (whether by exercising outstanding options, transfer or otherwise).

Stockholders' Agents:as defined in the Agreement of Stockholders.

Subsidiary:each corporation or other Person in which a Person owns or controls, directly or indirectly, capital stock or
other equity interests representing more than 50% of the outstanding voting stock or other equity interests.

Surviving Corporation:defined in Section 1.1(a).

Tax:any federal, state, local or foreign income, alternative, minimum, accumulated earnings, personal holding company,
franchise, capital stock, profits, windfall profits, gross receipts, sales, use, value added, transfer, registration, stamp, premium, excise, customs duties, severance, environmental (including taxes
under section 59A of the Code), real property, personal property, ad valorem, occupancy, license, occupation, employment, payroll, social security, disability, unemployment, workers'
compensation, withholding, estimated or other similar tax, duty, fee, assessment or other governmental charge or deficiencies (including related interest, penalties and additions).

Tax Return:any return, report, declaration, form, claim for refund or information return or statement relating to Taxes,
including any schedule or attachment to it, and including any amendment to it.

Transaction Agreements:this Agreement, the Escrow Agreement, the Pre-Merger Agreement of Stockholders, the
Post-Merger Agreements of Stockholders, the Employment Agreements and the Non-Competition Agreements.

Treasury Regulations:the regulations prescribed under the Code.

Trust:defined in Section 1.2(a)(ii).

2001 Balance Sheet:the Company's audited balance sheet as of December 31, 2001 included in the Financial Statements.

2000 Stock Plan:the Company's 2000 Stock Plan, as amended.

54

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UK Listing Authority:The UK Financial Services Authority in its capacity as competent authority under the UK Financial
Services Act 1986.

U.S. Dollar Equivalent:For any amount of British pounds, the equivalent amount of U.S. dollars determined using the Exchange
Rate.

U.S. GAAP:United States generally accepted accounting principles, as in effect at the time of the relevant date of, or
period covered by, the applicable financial reports.

Virus:a computer program that performs an illicit activity or replicates itself on a computer or network of computers and
thereby damages other computer programs or data located on that computer or network or otherwise causes a defect in the operation of that computer or network.

ARTICLE IX

Miscellaneous

9.1.Expenses.



9.2.Confidentiality.The Parties will continue to be bound by the confidentiality agreement, dated
April 25, 2001 (the "Confidentiality Agreement") between Parent and the Company until the Effective Time, at which time the Confidentiality
Agreement will terminate automatically. The Company agrees that it will, and will use its best efforts to cause its officers, directors, employees, agents, advisers and Representatives to, hold in
strict confidence the data and information supplied by Parent (unless this information is or becomes readily ascertainable from public or published information) and will not, and will use its best
efforts to ensure that such other Persons do not, disclose that information to others without Parent's prior written consent.

9.3.Notices.All notices, requests, demands, waivers and other communications required or permitted to be given
under this Agreement will be in writing and will be deemed to have been duly given if (a) delivered personally,
(b) sent by certified or registered mail (airmail if sent internationally with postage prepaid, (c) sent
by next day or overnight mail or delivery or (d) sent by facsimile or telegram, as follows:

55

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or,
in each case, at such other address as specified in writing to the other Parties in accordance with this Section 9.3.

All
such notices, requests, demands, waivers and other communications will be deemed to have been received (w) if by personal delivery, on
the next Business Day after delivery, (x) if by next day or overnight mail or delivery, on the day delivered, or
(y) if by facsimile or telegram, on the next Business Day following the day after transmission (provided that a copy is also sent by overnight mail or
delivery with postage prepaid).

9.4.Governing Law; Submission to Jurisdiction.



56

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9.5.Binding Effect.This Agreement will be binding on and inure to the benefit of the Parties and their
respective heirs, successors and permitted assigns.

9.6.Assignment.No party to this Agreement can assign or transfer this Agreement without the other Parties'
prior written consent except that Parent, SHC or Merger Sub may assign this Agreement to any wholly-owned direct or indirect Subsidiary of Parent, providedthat no such assignment will affect Parent's,
SHC's or Merger Sub's obligations or liabilities under this Agreement.

9.7.No Third Party Beneficiaries.Except for the right of the Stockholders to receive the Merger Consideration
at or after the Effective Time, nothing in this Agreement confers any rights on any Person other than the Parties and their respective heirs, successors and permitted assigns.

9.8.Amendment; Waivers, etc.



9.9.Survival; Remedies.



57

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9.10.Entire Agreement.This Agreement, including the Company Disclosure Schedules and other Schedules and
Exhibits, the other Transaction Agreements and the Confidentiality Agreement constitute the entire agreement of, and supersede all prior agreements and understandings (both written and oral) between,
the Parties with respect to its subject matter.

9.11.Severability.If any provision (including any phrase, sentence, clause, section or subsection) of this
Agreement is invalid, inoperative or unenforceable for any reason, this will not make that provision invalid, inoperative or unenforceable in any other case or circumstance, or make any other
provision invalid, inoperative, or unenforceable.

9.12.Headings.The headings in this Agreement are for convenience only and do not affect its interpretation.

58

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9.13.Counterparts.This Agreement may be executed in several counterparts, each of which will be deemed an
original and all of which will together constitute one and the same instrument.

9.14.U.S. Securities Laws.This Agreement, the negotiations relating to it and the transactions contemplated by
it do not constitute an offer of Parent Ordinary Shares to any Person that is not an "accredited investor", as defined in Rule 501 under the Securities Act.

9.15.Guarantee of Performance.Parent will cause SHC and Merger Sub to perform their respective obligations
under this Agreement, subject to its terms and conditions, and shall guarantee their performance to the extent not so performed by SHC or Merger Sub.

59

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The Parties have duly executed this Agreement as of the date first written above.

| |  | SPIRENT PLC                 
| |  | ----------------------------
| |  | By:                         
| |  | SPIRENT HOLDINGS CORPORATION
| |  | By:                         
| |  | CANCUN ACQUISITION CORP.    
| |  | By:                         
| |  | CAW NETWORKS, INC.          
| |  | By:                         

S-1

---

---

---

AGREEMENT
AND PLAN OF MERGER

by
and among

SPIRENT
plc,

SPIRENT
HOLDINGS CORPORATION,

CANCUN
ACQUISITION CORP. and

CAW
NETWORKS, INC.

Dated
as of July 21, 2002

---

---

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TABLE OF CONTENTS

|                                              |  |                                                           |  |    |  | Page
|--------------------------------------------- |  | --------------------------------------------------------- |  | -- |  | ----
|ARTICLE I                                    
|The Merger                                   
|1.1.                                          |  | The Merger                                                |  | 1 
|1.2.                                          |  | Conversion of Stock                                       |  | 2 
|1.3.                                          |  | Treatment of Options                                      |  | 4 
|1.4.                                          |  | Closing; Effective Time                                   |  | 6 
|1.5.                                          |  | Escrow Arrangements; Repayment of Indebtedness to Company |  | 6 
|1.6.                                          |  | Exchange of Certificates                                  |  | 6 
|1.7.                                          |  | Legends; Restrictions                                     |  | 8 
|1.8.                                          |  | Shares of Dissenting Stockholders                         |  | 9 
|1.9.                                          |  | Earn-Out                                                  |  | 9 
|1.10.                                         |  | Actions With Respect to Non-Accredited Investors          |  | 12
|ARTICLE II                                   
|Representations and Warranties of the Company
|2.1.                                          |  | Authorization, etc                                        |  | 13
|2.2.                                          |  | Stockholders; Capitalization, etc.                        |  | 13
|2.3.                                          |  | No Conflicts, etc                                         |  | 14
|2.4.                                          |  | Corporate Status                                          |  | 14
|2.5.                                          |  | European Union Operations                                 |  | 15
|2.6.                                          |  | Financial Statements                                      |  | 15
|2.7.                                          |  | Undisclosed Liabilities, etc                              |  | 15
|2.8.                                          |  | Absence of Changes                                        |  | 16
|2.9.                                          |  | Tax Matters                                               |  | 17
|2.10.                                         |  | Assets                                                    |  | 18
|2.11.                                         |  | Real Property                                             |  | 19
|2.12.                                         |  | Contracts                                                 |  | 19
|2.13.                                         |  | Intellectual Property                                     |  | 21
|2.14.                                         |  | Insurance                                                 |  | 24
|2.15.                                         |  | Litigation                                                |  | 25
|2.16.                                         |  | Compliance with Laws and Instruments; Consents            |  | 25
|2.17.                                         |  | Environmental Matters                                     |  | 26
|2.18.                                         |  | Affiliate Transactions                                    |  | 26
|2.19.                                         |  | Employees, Labor Matters, etc.                            |  | 27
|2.20.                                         |  | Employee Benefit Plans and Related Matters; ERISA         |  | 27
|2.21.                                         |  | Immigration                                               |  | 29
|2.22.                                         |  | Accounts Receivable                                       |  | 29
|2.23.                                         |  | Inventories                                               |  | 29
|2.24.                                         |  | Customers; Sales Representatives                          |  | 30
|2.25.                                         |  | Suppliers; Raw Materials                                  |  | 30
|2.26.                                         |  | Products; Product and Service Warranties                  |  | 30
|2.27.                                         |  | Bank Accounts                                             |  | 31
|2.28.                                         |  | Exon-Florio                                               |  | 31
|2.29.                                         |  | Brokers, Finders, etc                                     |  | 31
|2.30.                                         |  | Disclosure                                                |  | 32
|                                              |  |                                                           |  |    |  |     

i

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|ARTICLE III                                                    
|---------------------------------------------------------------
|Parent's, SHC's and Merger Sub's Representations and Warranties
|3.1.                                                           
|3.2.                                                           
|3.3.                                                           
|3.4.                                                           
|3.5.                                                           
|ARTICLE IV                                                     
|The Company's Covenants                                        
|4.1.                                                           
|4.2.                                                           
|4.3.                                                           
|4.4.                                                           
|4.5.                                                           
|4.6.                                                           
|4.7.                                                           
|4.8.                                                           
|4.9.                                                           
|ARTICLE V                                                      
|Parent's, SHC's and Merger Sub's Covenants                     
|5.1.                                                           
|5.2.                                                           
|5.3.                                                           
|5.4.                                                           
|ARTICLE VI                                                     
|Conditions Precedent                                           
|6.1.                                                           
|                                                               
|                                                               
|6.2.                                                           
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               
|                                                               

ii

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|              |  | 6.2.15.                                   |  | Payment of Seller Transaction Expenses |  | 43
|------------- |  | ----------------------------------------- |  | -------------------------------------- |  | --
|              |  | 6.2.16.                                   |  | Identity of Holders of Options         |  | 43
|              |  | 6.2.17.                                   |  | Contractual Consents                   |  | 43
|              |  | 6.2.18.                                   |  | Cisco                                  |  | 43
|              |  | 6.2.19.                                   |  | Separation Agreements                  |  | 43
|6.3.          |  | Conditions to Obligations of the Company  |  | 43                                    
|              |  | 6.3.1.                                    |  | Representations, Performance, etc.     |  | 43
|              |  | 6.3.2.                                    |  | No Parent Material Adverse Effect      |  | 44
|              |  | 6.3.3.                                    |  | Counsel's Opinions                     |  | 44
|              |  | 6.3.4.                                    |  | Other Transaction Agreements           |  | 44
|              |  | 6.3.5.                                    |  | Corporate Proceedings                  |  | 44
|              |  | 6.3.6.                                    |  | Parent Ordinary Shares                 |  | 44
|ARTICLE VII  
|Termination  
|7.1.          |  | Termination                               |  | 45                                    
|7.2.          |  | Effect of Termination                     |  | 45                                    
|ARTICLE VIII 
|Definitions  
|8.1.          |  | Terms Generally                           |  | 46                                    
|8.2.          |  | Certain Terms                             |  | 46                                    
|ARTICLE IX   
|Miscellaneous
|9.1.          |  | Expenses                                  |  | 55                                    
|9.2.          |  | Confidentiality                           |  | 55                                    
|9.3.          |  | Notices                                   |  | 55                                    
|9.4.          |  | Governing Law; Submission to Jurisdiction |  | 56                                    
|9.5.          |  | Binding Effect                            |  | 57                                    
|9.6.          |  | Assignment                                |  | 57                                    
|9.7.          |  | No Third Party Beneficiaries              |  | 57                                    
|9.8.          |  | Amendment; Waivers, etc.                  |  | 57                                    
|9.9.          |  | Survival; Remedies                        |  | 57                                    
|9.10.         |  | Entire Agreement                          |  | 58                                    
|9.11.         |  | Severability                              |  | 58                                    
|9.12.         |  | Headings                                  |  | 58                                    
|9.13.         |  | Counterparts                              |  | 59                                    
|9.14.         |  | U.S. Securities Laws                      |  | 59                                    
|9.15.         |  | Guarantee of Performance                  |  | 59                                    

iii

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|Exhibits            |  |                                                                                           
|------------------- |  | ------------------------------------------------------------------------------------------
|Exhibit A           |  | Form of Certificate of Incorporation of the Surviving Corporation                         
|Exhibit B           |  | Form of By-Laws of the Surviving Corporation                                              
|Exhibit C-1         |  | Form of Rollover Old Restricted Stock Agreement                                           
|Exhibit C-2         |  | Form of Rollover Early Exercise Restricted Stock Agreement                                
|Exhibit D           |  | Certificate of Merger                                                                     
|Exhibit E           |  | Form of Employment Agreement                                                              
|Exhibit F           |  | Form of Escrow Agreement                                                                  
|Exhibit G           |  | Form of Stock Option Assumption Agreement                                                 
|Exhibit H           |  | Form of Non-Competition Agreement                                                         
|Exhibit I           |  | Form of Opinion of Venture Law Group                                                      
|Exhibit J-1         |  | Form of Opinion of Linklaters                                                             
|Exhibit J-2         |  | Form of Opinion of Debevoise & Plimpton                                                   
|Exhibit K           |  | Post-Merger Agreement of Stockholders                                                     
|Exhibit 2.2(a)      |  | List of Company Stockholders                                                              
|Exhibit 2.2(d)      |  | List of Optionholders                                                                     
|Exhibit 2.8(v)      |  | Accounts Payable over $25,000 since December 31, 2001                                     
|Exhibit 2.8(vi)     |  | Increases in compensation since December 31, 2001                                         
|Exhibit 2.12(a)(ii) |  | Outstanding promissory notes related to the purchase of stock or exercise of option grants
|Exhibit 2.13(g)     |  | Due Registration                                                                          
|Exhibit 2.26(b)     |  | Standard Product and Service Warranties                                                   
|
|Schedule 2.2        |  | Stockholders; Capitalization, etc.                                                        
|Schedule 2.3        |  | No Conflicts, etc.                                                                        
|Schedule 2.4        |  | Corporate Status                                                                          
|Schedule 2.5        |  | European Union Operations                                                                 
|Schedule 2.7        |  | Undisclosed Liabilities, etc.                                                             
|Schedule 2.8        |  | Absence of Changes                                                                        
|Schedule 2.9        |  | Tax Matters                                                                               
|Schedule 2.10       |  | Assets                                                                                    
|Schedule 2.11       |  | Real Property                                                                             
|Schedule 2.12       |  | Contracts                                                                                 
|Schedule 2.13       |  | Intellectual Property                                                                     
|Schedule 2.14       |  | Insurance                                                                                 
|Schedule 2.16       |  | Compliance with Laws and Instruments; Consents                                            
|Schedule 2.18       |  | Affiliate Transactions                                                                    
|Schedule 2.20       |  | Employee Benefit Plans and Related Matters; ERISA                                         
|Schedule 2.24       |  | Customers; Sales Representatives                                                          
|Schedule 2.26       |  | Products; Product and Service Warranties                                                  
|Schedule 2.27       |  | Bank Accounts                                                                             
|Schedule 5.4        |  | Earn-Out Conditions                                                                       

iv

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