Seems very trivial but I'm confused which one of these correctly define transmission time.
Time taken by a message to reach receiver.
Time taken to push message on the link by the sender.
Which one is correct one?
Transmission time is the time from the first bit until the last bit of a message has left the transmitting node. Or, in simple word it's the amount of time required for the router to push out the packet.
Packet transmission time = Packet size / Bit rate
Reference :