Apple has 
entered into an agreement with Cisco to share the trademark “iPhone”. US law 
allows two companies to use the same trademark until it becomes “confusingly similar” to consumers.
In accordance with the agreement between Apple and Cisco, both companies can use the “iPhone” trademark in all countries of the world (by the way, in many countries it was 
registered with Apple , so the agreement is mutually beneficial).
In addition, Apple and Cisco have agreed on cooperation in the field of security, public relations and relations with government agencies.