OSI/AS Management Programming Manual
ALTER PROFILE Command
Commands and Responses
056785 Tandem Computers Incorporated 5–67
ZALT-CLASS
is the alternative protocol class to be used if the class specified in ZCLASS is
not supported by the remote system. If ZCLASS has the value ZOSI-VAL-
CLASS-0, then ZALT-CLASS is not applicable. The values for this field are the
same as for ZCLASS.
The valid combinations of preferred protocol class and alternative protocol
class are as follows:
ZCLASS ZALT-CLASS
0 not applicable
1 0 or 1
2 0 or 2
3 0, 1, 2, or 3
4 0, 1, 2, 3, or 4
ZTPDU-SIZE
is the maximum size (in bytes) of a transport protocol data unit (TPDU). The
acceptable values for this field are 128, 256, 512, 1024, 2048, 4096, and 8192
bytes. The values 4096 and 8192 are valid only when ZCLASS is 1, 2, 3, or 4.
For X.25 subnetworks: OSI/TS will adjust the value of ZTPDU-SIZE to not
exceed the value of the X25AM SYSGEN attribute MAXIOSIZE.
ZXSUM
specifies whether the checksum field is added to each TPDU. This field
applies only to protocol class 4 communication. If this field is set to
ZSPI-VAL-TRUE, the checksum field is added; if it is set to ZSPI-VAL-FALSE,
the checksum is not added.
ZEXT-FRMT
specifies whether the credit and sequence number of the TPDUs should be in
extended format. This field applies only to protocol class 2, 3, or 4
communication. If this field is set to ZSPI-VAL-TRUE, the extended format is
used; if it is set to ZSPI-VAL-FALSE, the normal format is used.
ZMULTIPLEX
specifies whether multiple outgoing transport connections are allowed to be
mapped onto one network connection. This field applies only to protocol class
2, 3, or 4 communication over a connection-mode network service (CONS;
X.25 is an example). If this field is set to ZSPI-VAL-TRUE, multiplexing is
attempted; if it is set to ZSPI-VAL-FALSE, multiplexing is not attempted.
Multiplexing requires that two or more transport connections have the same
local and remote NSAP addresses; have ZCLASS set to 2, 3, or 4; and have
ZMULTIPLEX set to ZSPI-VAL-TRUE. If these conditions are met, the