| Business/Market Regions |
| |
| Americas |
| Sprint |
| Advantex Communications |
| Alestra |
| Alltel Communications |
| AT&T |
| BCP Cellular (Brazil) |
| Bell Canada |
| Bell Mobility |
| Bell Mobility Wireless |
| Bell South |
| C&W |
| CC Comunications |
| CEI Conestoga Telephone |
| Centennial de Puerto Rico |
| Century Tel |
| Cincinnati Bell |
| Cingular |
| Cisco MeetingPlace |
| Citizens Telephone Cooperative Inc |
| Columbia Fiber (formerly Avista) |
| Comporium Wireless LLC |
| Cox Communications |
| D&E Communications |
| Embratel (Brazil) |
| Empire Telephone Co. |
| Foresthill Telephone Co. |
| Frontier Communications Corp |
| Genesys |
| Granite State Telephone Inc |
| Harrisonville Telephone |
| HTC Telephone |
| ICG |
| KMC Telecom Inc |
| Linx |
| MCI |
| Metrocall |
| Mindwireless |
| Nortel Networks |
| North Pittsburgh Telephone Co. |
| Pioneer Telephone |
| Prevare |
| Qwest |
| Radiomovil DIPSA, S.A. de C.V./Telcel (Mexico) |
| Rogers Wireless |
| SBC |
| Skytel Communications |
| Surewest |
| TDS Telecommunication Corp |
| Telecom Economia (Billing Audit Services for Brazil) |
| Telefonica DID Services (Brazil) |
| Telefonos de Mexico |
| Telemar (Analog Lines, Brazil) |
| Telesp Celular/Vivo Empresas (Brazil) |
| Teletrim Pager (Brazil) |
| Telus |
| TXU Communication Ventures Co |
| Verizon |
| Warwick Valley Telephone Co. |
| XO Communications |
|
| |
|
| |
| |
| Asia Pacific |
| C&W |
| Beijing Telecom |
| Bharat Sanchar Nigam Limited (BSNL) |
| Bharti |
| BPL Mobile |
| Chengdu Telecom |
| China Telecom |
| Chung Hwa Telecom |
| CNC |
| Dacom |
| Easycall |
| Equant |
| Far East Tone |
| Gap Communications |
| Guanzhou Telecom |
| Hong Kong CSL Limited |
| Japan Telecom |
| Jens |
| KDDI |
| Korea Telecom |
| KTF Telecom |
| LG Telecom |
| Mahanagar Telecom Nigam Limited |
| Marubeni Telecom |
| Maxis |
| MCI |
| NewZealand Telecom |
| NTT |
| Orange |
| PCCW |
| PowerNets (PoweredCom) |
| Prism Telecom |
| Shanghai Telecom |
| Shenyang Telecom |
| Shenzhen Telecom |
| SingTel |
| SK Telecom |
| Sprint |
| StarHub |
| TATA Teleservices Limited |
| Telekom Malaysia |
| Telephone Organization of Thailand (TAT) |
| Telstra |
| The Communication Authority of Thailand (CAT) |
| Time.net |
| TM Cellular Sdn Bhd |
| TT DotCom Sdn Bhd |
| TTNet Services |
| VSNL |
| Wireworks (NDL) |
|
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| |
| |
| Europe, Middle East and Africa (EMEA) |
| Arcor |
| Belgacom |
| Bezeq |
| BT |
| C&W |
| Cellcom |
| Checkmate |
| Colt |
| Deutsche Telekom |
| EasyNet |
| Eircom |
| Elisa |
| Equant |
| France Telecom |
| ISKY |
| KPN |
| Leasing West |
| lectronic |
| Mobilkom Austria |
| Morocutti-Electronic |
| MTS |
| NeckarCom |
| O2 |
| Opta |
| Orange |
| Safenames |
| SNT (splitted off from KPN) |
| Sonera |
| Sonofon |
| Sovintel |
| Swisscom |
| Teamphone |
| Telecom Italia |
| Teledenmark |
| Telefonica de Espana |
| Telekom Austria |
| Telia |
| T-Mobile |
| T-Systems |
| Vodafone |
| Wind |
| Windsor Telecom |
|
