TCP/IP Protocol Suite
As stated previously, SNMP is part of the TCP/IP protocol suite. Therefore, to
understand how SNMP messages (i.e., GET or SET requests or replies) are
exchanged between an SNMP manager (i.e., the client) and an SNMP-managed
device (i.e., the agent, such as Larscom’s Access-T), it is helpful to know
something about the TCP/IP protocol suite.
The TCP/IP protocol suite is a set of layered protocols for inter-computer
communication. It provides a connectionless, packet delivery system. Each
layer of the protocol is responsible for different communication functions.
Figure 1-8 provides an example of TCP/IP protocol layers for an SNMP
application.
Figure 1-8. TCP/IP Protocol Layers for an SNMP Application
RS232 Bit Transmission
SNMP
Manager
Access-T
(SNMP-Managed Device)
User
Datagram
Protocol
(UDP)
Internet
Protocol (IP)
SLIP or PPP
SLIP or PPP
Simple Network
Management
Protocol (SNMP)
User
Datagram
Protocol
(UDP)
Internet
Protocol (IP)
Simple Network
Management
Protocol (SNMP)
Application Layer
Transport Layer
Network Layer
Link Layer
Chapter 1
ACST-0351-005
Introduction
June 1996
1-20