OSI/AS Management Programming Manual

INFO SERVICE Command
Commands and Responses
5–150 056785 Tandem Computers Incorporated
For LAN networks, and for X.25 networks when the Layer 3 attribute ZIP-X25-
SNDCF is set to ZSPI-VAL-TRUE, ZCLASS is always ZOSI-VAL-CLASS-4.
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.
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.
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
maximum number of outgoing transport connections that can be multiplexed
is determined by the Layer 3 SERVICE attribute ZX25NCON-MULTIPLEX.
ZREXMIT-TIMEOUT
is the maximum amount of time that the transport entity should wait for an
acknowledgment before resending the TPDU. This field applies only to
protocol class 4 communication. The waiting time is expressed in hundredths
of a second (0.01 seconds per increment). The values range from 100 (1
second) through 3000 (30 seconds).