AT&T is a US-based telecoms company, and the second largest provider of mobile services and the largest provider of fixed telephone services in the US.
Avaya is a multinational technology company that specializes in cloud communications and workstream collaboration solutions that define the future of work and the customer experience.
Nortel Norstar is a small-office digital PBX introduced by Nortel Networks. It is based on the same internal design and instruction set as Nortel's earlier SL-1 and DMS systems, allowing it to support features such as integrated voice messaging (Meridian Mail), automatic call distribution and other features.
Cisco Routers provides intent-based networking for the WAN, LAN, and cloud. These routers include advanced analytics, application optimization, automated provisioning, and integrated security to deliver a complete solution.