1. Accenture PLC
2. Amdocs Inc.
3. AT&T Inc.
4. Cisco Systems Inc.
5. Deutsche Telekom AG
6. Fujitsu Limited
7. GTT Communications Inc.
8. Huawei Technologies Co. Ltd.
9. International Business Machines Corporation
10. Nokia Corporation
11. NTT Data Corporation
12. Tech Mahindra Limited
13. Telefonaktiebolaget LM Ericsson
14. Verizon Communications Inc.
15. Vodafone Group PLC