selective ringing

See distinctive ringing.

• Reed-Solomon (RS)
• Reference Model
• Reference Point Q
• Reference Point R
• Reference Point S
• Reference Point T
• Reference Point U
• Reference Point V
• reflection
• reflection
• reflection grating
• reflection grating
• reflector
• ReFLEX
• refraction
• refractive index
• refresh rate
• regenerative repeater
• Regional Bell Operating Company (RBOC)
• Regional Internet Registry (RIR)
• register
• registered jack (RJ)
• registered port
• Registration/Admission/Status (RAS)
• registration authority (RA)