OSI/TS Management Programming Manual

ALTER SU Command
Commands and Responses
5–64 056786 Tandem Computers Incorporated
ZTPDU-SIZE
specifies the maximum length of a transport protocol data unit (TPDU) in
bytes. Acceptable values are 128, 256, 512, 1024, 2048, 4096, and 8192. 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. Use the STATUS SU
command to determine the actual ZTPDU-SIZE used when the connection
was established.
ZXSUM
specifies whether the checksum field is added to the transport protocol data
unit. This parameter is applicable only if the preferred transport protocol class
is 4.
ZEXTENDED-FRMT
specifies whether the credit and sequence number of transport protocol data
units should be in the extended format. If the parameter value is ZSPI-VAL-
TRUE, extended format is used. If the parameter value is ZSPI-VAL-FALSE,
the normal format is used. This parameter is applicable only for transport
protocol classes 2, 3, and 4.
ZMULTIPLEX
specifies whether more than one outgoing transport connection is mapped to
one network connection (ZSPI-VAL-TRUE) or not (ZSPI-VAL-FALSE). The
default value is ZSPI-VAL-FALSE. To be able to multiplex, two or more
subdevices must have ZMULTIPLEX ON (ZSPI-VAL-TRUE) and have the
same local and remote NSAPs. If these conditions are met, the maximum
number of outgoing transport connections that are multiplexed together is
determined by the value of the Layer 3 service attribute ZX25NCON-
MULTIPLEX, described under the ALTER SERVICE command. This attribute
is valid only when ZCLASS is ZOS4-VAL-CLASS-2, ZOS4-VAL-CLASS-3, or
ZOS4-VAL-CLASS-4. This attribute is used only for outgoing connections on
X.25 networks.
ZEXPEDITED
specifies whether the transport expedited data transfer service is supported.
This is applicable only for transport protocol classes 1, 2, 3, and 4.
ZREXMIT-TIMEOUT
specifies the time, in units of 0.01 seconds, before which an unacknowledged
TPDU is retransmitted. Acceptable values range from 100 (1 second) through
3000 (30 seconds), with a default value of 1000 (10 seconds). This parameter is
applicable only for protocol class 4.