**EXHIBIT No. 21**

 

**Tellabs Inc. and Subsidiaries**

**Subsidiaries of the Registrant**

**as ofDecember 30, 2005**

** **
| **Name**                                                        | ** ** | **State or Other  Jurisdiction of  Incorporation** |
|-----------------------------------------------------------------|------------|-------------------------------------------------------------------|
| Tellabs  San Jose, Inc.                                         |       | Delaware                                                          |
| Tellabs  Reston, Inc.                                           |       | Delaware                                                          |
| White  Oak Merger Corp.                                         |       | Delaware                                                          |
| NetCore  Systems, Inc.                                          |       | Delaware                                                          |
| NetCore Securities  Corporation                                 |       | Delaware                                                          |
| Salix  Technologies, Inc.                                       |       | Delaware                                                          |
| Future  Networks, Inc.                                          |       | Georgia                                                           |
| Tellabs  Petaluma, Inc.                                         |       | Delaware                                                          |
| Tellabs Vienna, Inc.                                            |       | Delaware                                                          |
| Advanced Fibre Technology  Communications (HK) Limited          |       | Hong  Kong                                                        |
| Hangzhou AFTEK  Communication Company, Ltd.                     |       | China                                                             |
| Advanced Fibre  Communications (HK) Limited                     |       | Hong  Kong                                                        |
| AFC Foreign Sales  Corporation                                  |       | U.S.  Virgin Islands                                              |
| Tellabs North America, Inc.                                     |       | Delaware                                                          |
| Tellabs Bedford, Inc.                                           |       | Delaware                                                          |
| AccessLan India                                                 |       | India                                                             |
| AFC India Private Limited                                       |       | India                                                             |
| Advanced Fibre  Communications International GmbH               |       | Switzerland                                                       |
| Advanced Fibre  Communications Mexico S. de R.L. de C.V.        |       | Mexico                                                            |
| Advanced Fibre  Communications International Limited            |       | Cayman  Islands                                                   |
| Advanced Fibre  Communications U.K. Limited                     |       | United  Kingdom                                                   |
| AFC Harris Multimedia  Communications Private Limited           |       | Mauritius                                                         |
| AFC Harris Multimedia  Communications Limited                   |       | India                                                             |
| Tellabs  Mexico, Inc.                                           |       | Delaware                                                          |
| Tellabs de Mexico, S.A. de  C.V.                                |       | Mexico                                                            |
| Tellabs  TG, Inc.                                               |       | Delaware                                                          |
| Tellabs Transport Group,  Inc.                                  |       | Quebec                                                            |
| Tellabs  Nevada Holding Corporation                             |       | Nevada                                                            |
| Tellabs Treasury Holdings  Corporation                          |       | Nevada                                                            |
| Tellabs Equity Holding  Corporation                             |       | Nevada                                                            |
| Tellabs Securities Holding  Corporation                         |       | Nevada                                                            |
| Tellabs  Operations, Inc.                                       |       | Delaware                                                          |
| Telecommunications  Laboratories, Inc.                          |       | Delaware                                                          |
| Tellabs Export, Inc.                                            |       | Delaware                                                          |
| Tellabs Japan, Inc.                                             |       | Delaware                                                          |
| Tellabs Manufacturing, Inc.                                     |       | Delaware                                                          |
| Tellabs International, Inc.                                     |       | Illinois                                                          |
| Tellabs Communications  Canada Ltd.                             |       | Canada                                                            |
| Tellabs do Brazil, Ltda.                                        |       | Brazil                                                            |
| Tellabs H.K. Ltd.                                               |       | Hong  Kong                                                        |
| Tellabs Pty. Ltd.                                               |       | Australia                                                         |
| Tellabs International de  Mexico                                |       | Mexico                                                            |
| Tellabs Asia Pacific  Private Limited                           |       | Singapore                                                         |
| Tellabs (Thailand) Co.,  Ltd.                                   |       | Thailand                                                          |
| Tellabs Korea, Inc.                                             |       | Korea                                                             |
| Tellabs India Private  Limited                                  |       | India                                                             |
| Tellabs Communications  International Ltd.                      |       | China                                                             |
| Tellabs de Venezuela, S.A.                                      |       | Venezuela                                                         |
| Tellabs Communications  (Malaysia) Sdn Bhd                      |       | Malaysia                                                          |
| Tellabs Malaysia Sdn Bhd (49% joint venture)                    |       | Malaysia                                                          |
| Tellabs Holdings, B.V.                                          |       | The  Netherlands                                                  |
| Tellabs Enterprises B.V.                                        |       | The  Netherlands                                                  |
| Tellabs Oy                                                      |       | Finland                                                           |
| Kiinteisto Oy Mestarinkaare                                     |       | Finland                                                           |
| Kiinteisto Oy Sinimaentie 6                                     |       | Finland                                                           |
| Tellabs Denmark A/S                                             |       | Denmark                                                           |
| Tellabs Communications  (India) Private Limited                 |       | India                                                             |
| Kring – Tellabs India  Private Limited (49% joint venture) |       | India                                                             |
| Tellabs Holdings, Ltd.                                          |       | Ireland                                                           |
| Tellabs (Ireland) Ltd.                                          |       | Ireland                                                           |

 

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| Tellabs Ltd.                             |   | Ireland          |
|------------------------------------------|--------|------------------|
| Tellabs Research Ltd.                    |   | Ireland          |
| Tellabs Communications Ireland Limited   |   | Ireland          |
| Tellabs Communications Technologies      |   | Ireland          |
| Tellabs EMEA Holdings, Ltd.              |   | Ireland          |
| Tellabs AB                               |   | Sweden           |
| Tellabs (S.A.)  (Proprietary) Limited    |   | South  Africa    |
| Tellabs SAS                              |   | France           |
| Tellabs Italia S.r.l.                    |   | Italy            |
| Tellabs Netherlands B.V.                 |   | The  Netherlands |
| Tellabs Poland Sp. z o.o.                |   | Poland           |
| Tellabs Southern Europe  S.A.            |   | Spain            |
| Tellabs GmbH                             |   | Germany          |
| Tellabs Austria Vertriebs  GmbH          |   | Austria          |
| Tellabs Norway A/S                       |   | Norway           |
| Tellabs U.K. Ltd.                        |   | United  Kingdom  |
| Tellabs Communications UK  Limited       |   | United  Kingdom  |
| E. Coherent Communications  Systems Ltd. |   | United  Kingdom  |

 

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