|  | 11.6 | Other Network Layer Services
| 11.6.3 | Comparing connectionless and connection-oriented network processes
Connectionless network processes are often referred to as packet switched. In these processes, as the packets pass from source to destination, they can switch to different paths, as well as (possibly) arrive out of order. Devices make the path determination for each packet based on a variety of criteria. Some of the criteria (e.g. available bandwidth) may differ from packet to packet. Connection-oriented network processes are often referred to as circuit switched. These processes establish a connection with the recipient, first, and then begin the data transfer. All packets travel sequentially across the same physical circuit, or more commonly, across the same virtual circuit. The Internet is one huge connectionless network in which all packet deliveries are handled by IP. TCP (Layer 4) adds connection-oriented services on top of IP (Layer 3). TCP segments are encapsulated into IP packets for transport across the Internet. TCP provides connection-oriented session services to reliably deliver data.