OSI/TS Configuration and Management Manual

Introduction
OSI/TS Configuration and Management Manual—424831-001
1-8
Wide Area Networks
Transport protocol classes 0 through 4 can be used over wide area networks. Refer to
the X.25 Access Method (X25AM) Manual for more information on Compaq’s
implementation of X.25.
Figure 1-5
illustrates how OSI/TS uses SNDCF to implement IP over X.25 wide area
subnetworks (SNDCF is enabled). When SNDCF is enabled, the IPPDU is sent as data
in the X.25 frame.
In contrast, Figure 1-6
illustrates a X.25 wide area subnetwork connection with SNDCF
disabled. In this case, the TSP process only implements Transport Layer functions.
Figure 1-5. X.25 Wide Area Subnetworks: SNDCF Enabled
Figure 1-6. Wide Area Subnetworks: SNDCF Disabled
105CDT .CDD
Transport
Layer
Network
Layer
Data
Data Link
Layer
X25AM
SNDCF
IP
TSP
106CDT .CDD
Transport
Layer
Network
Layer
Data
Data Link
Layer
X25AM
TSP