<PAGE>
                                                              EXHIBIT 4.(a)(xxv)

                            DATED JANUARY 17, 2002

                       RED-M (COMMUNICATIONS) LIMITED (1)

                                     - and -

                             M WILSON AND OTHERS (2)

                                     - and -

                              MADGE NETWORKS NV (3)

                                     - and -

                               THE APAX FUNDS (4)

                                     - and -

                              THE AMADEUS FUNDS (5)

                                     - and -

                          INTEL CAPITAL CORPORATION (6)

       -------------------------------------------------------------------
                                  AMENDMENT TO
                             SHAREHOLDERS AGREEMENT
       -------------------------------------------------------------------




<PAGE>





                                                              Amendment Number 2


AMENDMENT TO SHAREHOLDERS AGREEMENT dated 17th January 2002

PARTIES:

(1)      RED-M (COMMUNICATIONS) LIMITED a company incorporated in England and
         Wales under Number 03985301 whose registered office is at Wexham
         Springs, Framewood Road, Wexham, Slough, Berkshire SL3 6PJ ("COMPANY").

(2)      THE PERSONS whose names and addresses are set out in Schedule 1.

(3)      MADGE NETWORKS NV a company incorporated in the Netherlands whose
         address is at Transpolis Schiphol Airport, Polaris Avenue, 23, 2132 JH
         Hoofddorp, The Netherlands ("MADGE").

(4)      AP V GMBH & CO KG, a company incorporated in Germany (registered no HRA
         78582) whose principal address is Nussbaumstrasse 8, 80336 Munich,
         Germany, APAX EUROPE V - A, L.P., a Delaware limited partnership
         established under the Delaware Revised Uniform Limited Partnership Act
         (the "EUROPE A FUND"), APAX EUROPE V - B, L.P., an English limited
         partnership established under the Limited Partnerships Act 1908 (the
         "EUROPE B FUND"), APAX EUROPE V-C GMBH & CO KG, a German limited
         partnership (Kommanditgesellschaft) established under the German Civil
         Code (Handelsgesetzbuch) (the "EUROPE C FUND"), APAX EUROPE V - D,
         L.P., an English limited partnership established under the Limited
         Partnerships Act 1908 (the "EUROPE D FUND"), APAX EUROPE V - E, L.P.,
         an English limited partnership established under the Limited
         Partnerships Act 1908 (the "EUROPE E FUND"), APAX EUROPE V - F, C.V., a
         Dutch limited partnership (commanditaire vennootschap) established
         under the Wetboek van Koophandel (the "EUROPE F Fund"), and APAX EUROPE
         V - G, C.V., a Dutch limited partnership (commanditaire vennootschap)
         established under the Wetboek van Koophandel (the "EUROPE G FUND"),
         each having its principal place of business at 13-15 Victoria Road, St.
         Peter Port, Guernsey, GY1 3ZD and each acting by its investment manager
         Apax Partners Europe Managers Limited whose registered office is at 15
         Portland Place, London W1B 1PT, (collectively referred to as "APAX" and
         individually referred to as an "APAX FUND").

(5)      AMADEUS II A, a limited partnership established in England under the
         Limited Partnership Act 1907, whose principal place of business is at 5
         Shaftesbury Road, Cambridge, CB2 2BW acting by its manager, AMADEUS
         CAPITAL PARTNERS LIMITED having its registered office at 5 Shaftesbury
         Road, Cambridge, CB2 2BW ("AIIA"), AMADEUS II B, a limited partnership
         established in England under the Limited Partnership Act 1907, whose
         principal place of business is at 5 Shaftesbury Road, Cambridge, CB2
         2BW acting by its manager, AMADEUS CAPITAL PARTNERS LIMITED having its
         registered office at 5 Shaftesbury Road, Cambridge, CB2 2BW ("AIIB"),
         AMADEUS II C, a limited partnership established in England under the
         Limited Partnership Act 1907, whose principal place of business is at 5
         Shaftesbury Road Cambridge CB2 2BW acting by its


                                       2

<PAGE>
         manager, AMADEUS CAPITAL PARTNERS LIMITED having its registered office
         at 5 Shaftesbury Road, Cambridge, CB2 2BW ("AIIC"), AMADEUS II GMBH &
         CO KG, a German limited partnership acting by its manager AMADEUS
         CAPITAL PARTNERS LTD ("AKG"), AMADEUS II AFFILIATES, a limited
         partnership established in England under the Limited Partnership Act
         1907, whose principal place of business is at 5 Shaftesbury Road,
         Cambridge, CB2 2BW acting by its manager, AMADEUS CAPITAL PARTNERS
         LIMITED having its registered office at 5 Shaftesbury Road, Cambridge,
         CB2 2BW ("AII AFFILIATES"). (AIIA, AIIB and AIIC, AKG and AII
         Affiliates collectively referred to as "AMADEUS" and individually to as
         an "AMADEUS FUND").

(6)      INTEL CAPITAL CORPORATION a Cayman Islands company whose registered
         office is situated at the offices of Caledonian Bank & Trust Limited,
         Caledonian House, PO Box 1043, George Town, Grand Cayman, Cayman
         Islands ("INTEL").

RECITALS:

WHEREAS the parties entered into a Shareholders Agreement dated September 10,
2001 (the "Shareholders Agreement").

WHEREAS in consideration of the mutual covenants herein the parties wish to
amend the terms of the Shareholders Agreement on the terms and conditions of
this amendment agreement.

IT IS AGREED:

1.       Clause 8 of the Shareholders Agreement be substituted in its entirety
by the following Clause:-

"8.      MADGE NON-COMPETE UNDERTAKINGS*

8.1      Madge undertakes with the Company that, except with the written consent
         of the Board (excluding the Madge Directors) and as covered by the
         exception in Clause 8.2 below:

         8.1.1    that for a period commencing on the date hereof and expiring
                  on the date twelve months after the Termination Date it will
                  not whether by itself, through its employees or agents or
                  otherwise howsoever and whether on its behalf or on behalf of
                  any person, firm, company or other organisation, directly or
                  indirectly:

                  8.1.1.1  in competition with any member of the Group within
                           the Restricted Area be engaged or otherwise
                           interested in the business of manufacturing,
                           designing, distributing, selling, supplying or
                           otherwise dealing with Goods with the exception of
                           wireless NIC Cards (for use in PC's and Laptops only,
                           not to be used in PDA's and other handheld devices);

                  8.1.1.2  in competition with any member of the Group, solicit
                           business from or canvas any Customer or Prospective
                           Customer if such solicitation or canvassing is in
                           respect of Goods;

----------
* Confidential Treatment for various items in this section requested by Madge
Networks N.V.


                                       3
<PAGE>


                  8.1.1.3  in competition with any member of the Group accept
                           orders for Goods from any Customer or Prospective
                           Customer;

                  8.1.1.4  solicit or induce or endeavour to solicit or induce
                           any person who on the Termination Date was a
                           director/manager of any member of the Group to cease
                           working for or providing services to the Group,
                           whether or not any such person would thereby commit a
                           breach of contract;

                  8.1.1.5  employ or otherwise engage in the business of
                           manufacturing, distributing, designing, selling,
                           supplying or otherwise dealing with Goods any person
                           who was during the 12 months preceding the
                           Termination Date employed or otherwise engaged by any
                           member of the Group and who by reason of such
                           employment or engagement is in possession of any
                           trade secrets or confidential information relating to
                           the business of any member of the Group or who has
                           acquired influence over its Customers and Prospective
                           Customers;

                           interfere or seek to interfere with the continuance
                           of supplies to any member of the Group (or the terms
                           of such supplies) from any suppliers who shall have
                           been supplying components for material or services to
                           any member of the Group;

         8.1.2    for the purposes of clauses 8.1 to 8.10 the following words
                  shall have the following meanings:

                  8.1.2.1  "GOODS" shall mean Bluetooth or 802.11 wireless LAN
                           or PAN networking solutions or directly competing
                           technology with the exception of wireless NIC Cards
                           (for use in PC's and Laptops only, not to be used in
                           PDA's or other handheld devices);

                  8.1.2.2  "SERVICES" shall mean the provision of managed
                           services relating to Bluetooth or 802.11 wireless LAN
                           or PAN networking solutions or directly competing
                           technology;

                  8.1.2.3  "CUSTOMER" shall mean any person, firm, company, or
                           other organisation whatsoever to whom or which any
                           member of the Group distributed, sold or supplied
                           Goods during the one year immediately preceding the
                           Termination Date;

                  8.1.2.4  "PROSPECTIVE CUSTOMER" shall mean any person, firm,
                           company or other organisation whatsoever with whom or
                           which any member of the Group had negotiations or
                           discussions regarding the possible distribution, sale
                           or supply of Goods during the twelve months
                           immediately preceding the Termination Date;

                  8.1.2.5  "RESTRICTED AREA" shall mean

                           8.1.2.5.1  United Kingdom, the European Union, the
                                      United States, Canada and Japan; and




                                       4
<PAGE>

                           8.1.2.5.2  any other country in the world where, on
                                      the Termination Date, any member of the
                                      Group was engaged in the manufacture,
                                      distribution, design, sale or supply or
                                      otherwise dealt with Goods;

                  8.1.2.6  "TERMINATION DATE" shall mean the date that Madge
                           ceases to hold 20% or more of the issued share
                           capital of the Company.

8.2      Madge shall be permitted to manufacture, design, distribute, sell,
         supply or otherwise deal with wireless NIC Cards (for use in PC's and
         Laptops only, not to be used in PDA's and other handheld devices).

8.3      Madge, during the period that Clause 8.1 is in effect, agrees not to,
         through its employees or agents or otherwise howsoever and whether on
         its own behalf or on behalf of any person, firm, company or other
         organisation, directly or indirectly, distribute, sell or otherwise
         deal with Goods which have been manufactured, designed, distributed,
         sold, or supplied by the following companies who are deemed to directly
         compete with the Company's Access Points, Access Servers and Genos
         products: XXX (together referred to as the "Competitors"). Subject
         always to the provisions of Clause 8.1, this Clause shall not apply
         to:-

         8.3.1    any companies or businesses which are acquired by any of the
                  Competitors after the date of this amendment agreement and
                  which companies or businesses have executed a legally binding
                  agreement with Madge prior to such acquisition. In the event
                  that this subclause 8.3.1 applies, Madge shall not enter into
                  any further relationship, agreement or arrangement with such
                  companies or businesses which is outside the terms of the
                  legally binding agreement referred to above in this subclause
                  8.3.1;

         8.3.2    any companies in which any of the Competitors have a minority
                  interest provided such companies are not also listed as one of
                  the Competitors in Clause 8.3.

8.4      Subject always to the provisions of Clause 8.1, in the event Madge
         wishes to include Goods or Services in the product range of Madge
         during the period that Clause 8.1 is in effect, Madge shall give the
         Company the opportunity to be the exclusive supplier to Madge of such
         Goods or Services in accordance with the following procedure:

                  (a) Madge shall give the Company written notice of its
                  intention to include Goods or Services in its product range as
                  soon as reasonably practicable, such written notice to include
                  sufficient details to enable the Company to provide a quote
                  for such Goods or Services;

                  (b) the Company shall notify Madge within thirty (30) days of
                  receiving written notice from Madge pursuant to subclause (a)
                  as to whether it wishes to supply such Goods or Services and
                  shall provide Madge with a written quote for such Goods or
                  Services;

                  (c) Following receipt from the Company of the written quote in
                  accordance with subclause (b), Madge shall be entitled to
                  approach third parties for the purposes only of obtaining
                  similar quotes for such Goods and Services. Subject to


                                       5

<PAGE>

                  the terms of any confidentiality agreements Madge may have
                  entered into with third parties, Madge shall give the Company
                  the opportunity (if necessary) to improve its quote. Madge
                  shall act reasonably and in good faith and shall not make any
                  unreasonable requests of the Company. If the Company's quote
                  is at least as competitive as any quote from a third party and
                  Madge and the Company can agree terms Madge shall place such
                  business for such Goods and Services solely with the Company.

                  (d) If the Company notifies Madge that the Company does not
                  wish to supply the Goods or Services, fails to notify Madge
                  within the thirty (30) day period referred to in subclause
                  (b), fails to provide a competitive quote, or the parties fail
                  to agree upon the terms of supply by the Company in accordance
                  with subclause (c) then;

                            (i) if the Goods or Services requested by Madge
                  pursuant to this Clause are in the Company's immediate product
                  plan at the time of the request, Madge shall be permitted to
                  obtain such Goods or Services from a third party supplier
                  (subject always to the provisions of Clause 8.3) for resale
                  but shall not be permitted to design, develop or manufacture
                  the Goods or Services itself.

                           (ii) if the Goods or Services requested by Madge
                  pursuant to this Clause are not in the Company's immediate
                  product plan at the time of the request, then Madge shall be
                  permitted to obtain such Goods or Services from a third party
                  supplier (subject always to the provisions of Clause 8.3) for
                  resale and/or to design, develop or manufacture such Goods or
                  Services itself.

8.5      Madge (having taken independent legal advice) agrees with the Company
         that the above non-compete undertakings are reasonable and necessary
         for the protection of the legitimate interests of the Initial
         Investors.

8.6      While the above undertakings are considered to be reasonable it is
         agreed that if any such undertakings shall be adjudged to go beyond
         what is reasonable for the protection of the interests of the Company
         but would be reasonable if part or parts were deleted or modified, the
         relevant undertaking or undertakings shall apply with such deletion
         and/or modification as may be necessary to make it or them valid and
         effective.

8.7      Madge shall procure that each group company of Madge complies with this
         clause 8.

8.8      Nothing contained in this Clause 8 shall preclude or restrict Madge or
         a group company of Madge acquiring another company, group of companies,
         business or undertaking (the "ACQUIRED UNDERTAKING") whose business or
         businesses include(s) any of the businesses which would, following such
         acquisition, be subject to the restrictions set out in clause 8.1 and
         Clause 8.3 (the "RELEVANT BUSINESS") provided that the annual turnover
         of the Relevant Business as shown in the most recently audited annual
         accounts of the Acquired Undertaking prior to the date of the
         acquisition did not account for more than 5 per cent of the aggregate
         turnover of the Acquired Undertaking, as shown by such accounts and
         Madge shall ensure that such part of the Relevant Business as is
         subject to the restrictions set out in this clause 8 is disposed of
         within 6 months of acquisition to a third party or parties.









                                       6
<PAGE>

8.9      In relation to any Board meetings to consider, or action to be taken by
         the Company in respect of any breach or suspected breach by Madge of
         this clause 8, Madge shall procure that its Nominated Directors shall
         not attend such Board meetings (unless requested by the Initial
         Investors) and shall not vote thereat and will permit the prosecution
         of such matter by the Apax Director and Amadeus Director on behalf of
         the Board (or a committee of the Board appointed by them).

8.10     Notwithstanding the provisions of the above non-compete undertakings,
         in the event that:

         8.10.1   Madge shall during the term of this Agreement supply any
                  services within the Restricted Area, which compete with any
                  Services provided by the Company; or

         8.10.2   the Company shall during the term of this Agreement supply any
                  Services within the Restricted Area, which compete with any
                  services provided by Madge or any member of the Madge group;

         the board of Madge shall meet with the Board in order to resolve the
         conflict of interests between the respective businesses of the Company
         and Madge and the Company and Madge acting in good faith shall use
         their respective best endeavours to reach a workable solution to their
         mutual benefit."

2        This amendment agreement is supplemental to the Shareholders Agreement
         and the provisions of the Shareholders Agreement (as amended by this
         amendment agreement) shall accordingly remain in full force and effect.

3.       This amendment agreement may be executed in any number of counterparts,
         each of which when executed and delivered is an original, but all the
         counterparts together constitute the same document.

4.       This amendment agreement is governed by English law.

EXECUTED the day and year first before written.




                                   SCHEDULE 1
                       (Employee and Trustee Shareholders)


                                       7



<PAGE>



SIGNED for and on behalf of RED-M                   ) /s/ M WILSON
(COMMUNICATIONS) LIMITED in the presence of:        ) /s/ C ROBBINS





SIGNED by MICHAEL WILSON in the presence of:        ) /s/ M WILSON
                                                    ) /s/ C ROBBINS





SIGNED by SIMON GAWNE in the presence of:           ) /s/ S GAWNE
                                                    ) /s/ C ROBBINS





SIGNED by CLIVE MAYNE in the presence of:           ) /s/ C MAYNE
                                                    ) /s/ C ROBBINS




SIGNED by ALISON EDGE in the presence of:           ) /s/ A EDGE
                                                    ) /s/ C ROBBINS




SIGNED by DUNCAN SIMPSON in the presence of:        ) /s/ D SIMPSON
                                                    ) /s/ C ROBBINS




SIGNED for and on behalf of RED-M TRUSTEE LIMITED   ) /s/ A BRETT
in the presence of:                                 ) /s/ C ROBBINS


                                       8



<PAGE>

The Common seal of                                  ) /s/ TIM SCOTT WARREN
COMPASS TRUSTEES LIMITED was hereunto affixed       ) /s/ ALAN HARRISON
in the presence of:                                 ) /s/ WITNESS



SIGNED for and on behalf of MADGE  NETWORKS  NV in  ) /s/ M MALINA
the presence of:                                    ) /s/ K HALLGATE



SIGNED  for and on  behalf  of AP V GMBH & CO.  KG  )
by:                                                 ) /s/ DIRECTOR



EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-A, L.P. by:                ) /s/ P ENGLANDER



EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-B, L.P. by:                ) /s/ P ENGLANDER



EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-C, GMBH & CO. KG by:       ) /s/ P ENGLANDER



EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
managers of APAX EUROPE V-D, L.P. by:               ) /s/ P ENGLANDER
                                       9



<PAGE>

EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-E, L.P. by:                ) /s/ P ENGLANDER





EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-F, C.V. by:                ) /s/ P ENGLANDER





EXECUTED for and on behalf of APAX PARTNERS         )
EUROPE MANAGERS LIMITED acting in its capacity as   )
manager of APAX EUROPE V-G, C.V. by:                ) /s/ P ENGLANDER



EXECUTED for and on behalf of AMADEUS CAPITAL       )
PARTNERS LIMITED acting in its capacity as          )
manager of AMADEUS II A by:                         ) /s/ H HAUSER



EXECUTED for and on behalf of AMADEUS CAPITAL       )
PARTNERS LIMITED acting in its capacity as          )
manager of AMADEUS II B by:                         ) /s/ H HAUSER



EXECUTED for and on behalf of AMADEUS CAPITAL       )
PARTNERS LIMITED acting in its capacity as          )
manager of AMADEUS II C by:                         ) /s/ H HAUSER


                                       10


<PAGE>

EXECUTED for and on behalf of AMADEUS CAPITAL       )
PARTNERS LIMITED acting in its capacity as          )
manager of AKG by:                                  ) /s/ H HAUSER



EXECUTED for and on behalf of AMADEUS CAPITAL       )
PARTNERS LIMITED acting in its capacity as          )
manager of AII AFFILIATES by:                       ) /s/ H HAUSER



EXECUTED for and on behalf of INTEL CAPITAL         )
CORPORATION by:                                     )
                                                    )

By:      /s/ G KERSHAW

Name:    GARY KERSHAW

Title:   ASSISTANT TREASURER

                                       11