OSI/TS Configuration and Management Manual

NonStop Kernel File-System Interface
OSI/TS Configuration and Management Manual—424831-001
7-16
SETPARAM 10
Protocol Class (Octets 12 and 13)
This field indicates the current protocol class. The value is not significant if the
primary connection state is 4 (connection not established).
Maximum TPDU Size (Octets 14 and 15)
This field indicates the maximum TPDU size permitted, in octets.
Version Number (Octets 16 and 17)
This field specifies current Compaq version number of the OSI/TS software.
Additional Options (Octets 18 and 19)
This field specifies various services that can be requested on a transport
connection. The additional options bits have the meaning shown in Figure 7-4.
As you can see in Figure 7-4
, when bit 2 (the receipt confirmation bit) is set,
class 1 relies on the network service for acknowledgment of TPDUs. Since this
option is not available in X25AM, OSI/TS sets this bit to 0, meaning that the
alternative method—explicit AK variant—is used.
The content of this field is a Compaq implementation. It does not necessarily
have any relationship with the content of any TPDU.
Variable-Length Records (Beginning at Octet 20)
The portion of the status block that follows the fixed part, beginning at octet 20.
This part consists of a number of variable-length records. Figure 7-5 illustrates
the structure of each variable-length record.
Figure 7-4. Subdevice Status Block Additional Options Field
704CDT .CDD
123456789101112131415
Network Expedited Option in Class 1
Receipt Confirmation Option in Class 1
Checksum Option in Class 4
Transport Expedited Option
Most Significant Bit Least Significant Bit
Bit 0