230 Chapter 8: Establishing an X.25 Connection
Figure 8-3
The X.25 Layered Model
SVC deployments are significantly less maintenance intense. An SVC is simply a phone call
from one point to another. As mentioned, SVC implementations are dynamically set up and torn
down. They are not nailed up connections. They do tear down after some time of inactivity and
must be reestablished if additional data must traverse the link.
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X.25 (PLP)
LAPB
Physical
Physical
Data Link
Network
Transport
Session
Presentation
Application