6 configuring x.25, Chapter 6, Configuring x.25 -1 – Lucent Technologies 6000 User Manual
Page 287: Chapter 6: configuring x.25 -1, Chapter 6, “configuring x.25, Configuring x.25
MAX 6000/3000 Network Configuration Guide
6-1
6
Configuring X.25
The X.25 protocol operates at the network layer to provide virtual circuits and deliver such
services as multiplexing, in-sequence delivery of packets, transfer of addressing information,
segmentation and reassembly, flow control, error control, reset, and restart. Allocation of
logical channels can be either static (a permanent virtual circuit-PVC) or dynamic (a switched
virtual circuit-SVC).
X.25 is not as fast as newer protocols that operate at the data-link layer, leaving network-layer
functions to the processors at each end of the connection. However, X.25 became widely
established, especially in Europe, and remains in widespread use in many geographical areas.
The MAX unit supports a single physical X.25 connection. You must configure a physical link
and at least one logical link to an X.25 switch. Once you have configured a logical link in an
X.25 profile, depending on the applications (i.e., Connection profile for IP/X.25 or AO/DI),
you can configure individual IP-routing connections in Connection profiles.
The unit enables several terminals to share a single network line by performing the functions of
an X.25 Packet Assembler/Disassembler (PAD). The MAX PAD supports a unique command
X.28 interface, and you can configure an X.3 profile to fine-tune PAD settings.
If you use X.25 on an ISDN connection, you can configure the D channel to transmit X.25
data. For example, Always On/Dynamic ISDN (AO/DI) can send low-bandwidth
transmissions over the D channel and add switched B channels as bandwidth requirements
increase. (For example, the D channel is usually sufficient for email transmissions, but not for
Configuring X.32 profiles for incoming switched X.25 connections . . . . . . . . . . . . . 6-27