Verilink 9000 Series (34-00271) Product Manual - Manual (Page 260)

238 C HAPTER 13: X.25
Option B - No User Data
When this option is set, the MultiPro unit does not send any user data information in
a X.25 call request. Normally, the MultiPro unit transports information containing
the requesting station's address as well as the desired destination. If the MultiPro unit
is connecting to a foreign device, such as a Front End Processor, sending this
information is unnecessary since the receiving device does not know what the data
represents. In a worst-case situation, the receiving device may interpret the user data
according to its own settings and perform unwanted functions.
Option C - X.29 User Data
On occasion, it may be necessary for the MultiPro unit to place call requests to an
async PAD that requires X.29 information in the user data field. By turning on this
option, the MultiPro unit replaces its normal user data information with the
following hexadecimal values: 01 00 00 00. Care must be taken with this option,
however, since the MultiPro unit does not support X.29 interaction and does not
take any action on received X.29 information. This option is used simply to get the
receiving PAD to accept the call request.
LCN Calling Addr. Length Called Addr. Length Called Address Calling Address Facility Field User Data
DOWNLOAD CONFIG
MODE BACKUP NET ALARM POWER
PRISM 9111 T R A N S P O R T
®
Processor
Call Request
X
Figure 13-14 Typical Application with the No User Data Option
LCN Calling Addr. Length Called Addr. Length Called Address Calling Address Facility Field User Data
DOWNLOAD CONFIG
MODE BACKUP NET ALARM POWER
PRISM 9111 T R A N S P O R T
®
UNIX
Async
PAD
Hex: 01 00 00 00
Call Request
X.25
VT100
Terminal
Figure 13-15 Typical Application with the User Data Option