That should be a router.
A router is a networking device that forwards data on a network.
A router is a device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP's network. Routers are located at gateways, the places where two or more networks connect, and are the critical device that keeps data flowing between networks and keeps the networks connected to the Internet.
router networking/roo't*/ A device which forwards packets between networks. The forwarding decision is based on network layer information and routing tables, often constructed by routing protocols.
It is the time between successive packets.
Router
... packet-switching networks.
It is a fact that bridges forward packets faster when compared to routers. Because router takes time to find the shortest path between source and destination,whereas bridges directly forwards the packets.
The Answer is ICMP - A core protocol in the TCP/IP suite that notifies the sender that something has gone wrong in the transmission process and that packets were not delivered. Page 177. Networks + Guide to Networks 5th edition.
network address translation device
layer 3
Expedited Forwarding
hello packets