Page 753 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

remote terminals, and so on are found here. Numerous application-

specific protocols are found within this layer, such as the following:
Hypertext Transfer Protocol (HTTP)

File Transfer Protocol (FTP)

Line Print Daemon (LPD)

Simple Mail Transfer Protocol (SMTP)

Telnet

Trivial File Transfer Protocol (TFTP)

Electronic Data Interchange (EDI)

Post Office Protocol version 3 (POP3)

Internet Message Access Protocol (IMAP)

Simple Network Management Protocol (SNMP)

Network News Transport Protocol (NNTP)
Secure Remote Procedure Call (S-RPC)

Secure Electronic Transaction (SET)

There is a network device (or service) that works at the Application
layer, namely, the gateway. However, an Application layer gateway is a
specific type of component. It serves as a protocol translation tool. For
example, an IP-to-IPX gateway takes inbound communications from
TCP/IP and translates them over to IPX/SPX for outbound

transmission. Application layer firewalls also operate at this layer.
Other networking devices or filtering software may observe or modify
traffic at this layer.