
238 Chapter 7 • Configuring and Backing Up Permanent Connections
Data Terminal Equipment (DTE) and Data
Circuit-Terminating Equipment (DCE)
X.25 utilizes a connection-oriented service, which ensures that packets are
transmitted in order. The end-user connection is called DTE and the con-
nection on the network (carrier) side is called DCE (see Figure 7.3). The
user (DTE) can communicate with multiple users simultaneously on a
single physical line, with multiple logical channels. On one physical line
there can be as many as 4096 logical channels.
Packet Assembler/De-assembler (PAD)
In the early 80s, a majority of data processing was done utilizing asynchro- ...