Hi here is my entries for your consideration.
#164 using initial N and T, N in orange and blue, T in blue. the T using swosh for representing technologies arround the world.
#160 with unique wordmark (custom font) make people easyly remember the brand.
#165 more technologies.
#167 N and T in white space, and signal bar for representing VoIP communications.
hope you like it.
Best Regards,
AF