o acknowledge timer
Default: 3000 Value: 1-60000
Time (in milliseconds) to wait for an acknowledgment before using
error recovery procedures. The value of this characteristic
corresponds to the T1 parameter of HDLC. You can modify this
characteristic only when the entity is disabled.
o holdback timer
Default: 0 Value: 1-60000
Maximum time to wait before sending an acknowledgment supervisory
frame if no other frames carry the acknowledgment. A value of
zero means that the frame will be sent immediately if no I-frame
can be sent. You can modify this characteristic only when the
entity is disabled.
o link type
Operational mode of the HDLC link. The value of this
characteristic is a copy of the link type argument specified when
the entity is created. You cannot modify this characteristic.
o maximum data size
Default: 1500 Value: 262-65532
Maximum number of bytes that users of the data link can specify.
This number applies to both transmit and receive frames.
The value of this characteristic must be greater than or equal to
the value of the minimum data size characteristic. You can modify
this characteristic only when the entity is disabled.
o maximum unsequenced pdus
Default: 1 Value: 1-127
Maximum number of unsequenced I-frames that a primary or
secondary station can send in a single transmission. This
characteristic is not used if the link type characteristic is
balanced.
o minimum data size
Default: 576 Value: 262-65532
Minimum number of bytes that users of the data link can specify.
This number applies to both transmit and receive frames.
The value of this characteristic must be less than or equal to
the value of the maximum data size characteristic. You can modify
this characteristic only when the entity is disabled.
o physical line
Default: None Value: local entity name
Local entity name of the the Physical layer entity over which the
HDLC protocol is to operate.
This characteristic must have a value before the HDLC link is
enabled. You can modify this characteristic only when the entity
is disabled.
o preferred crc type
Default: Either Value: 16 bit, 32 bit, or either
CRC types available for negotiation. If the value of this
characteristic is either, the station will try to use 32-bit but
will use 16-bit if that is all that the remote station supports.
o preferred local station address
Default: 2 Value: 1-253
Address proposed for the local logical station during
negotiation. If there is no negotiation, the value of this
characteristic is the value that is used. If negotiation is
necessary, the value of this characteristic must be between 2
and 253. You can modify this characteristic only when the entity
is disabled.
o preferred maximum data size
Default: 1500 Value: 262-65532
Default size (in octets) of frames that the station receives and
transmits. This value is used only if the link initialization
does not specify a buffer value.
The value of this characteristic must lie between those of the
maximum data size and minimum data size characteristics. You can
modify this characteristic to a lower value only when the entity
is disabled.
o preferred window size
Default: 2 Value: 1-127
Window size to be offered during negotiation for both receive
and transmit frames. The value of this characteristic must be
compatible with that for the sequence modulus characteristic.
o profile (OpenVMS)
Simple name that can be used when the HDLC protocol is dependent
on network subscription time commitments pertinent to the Data
Link layer. The value of this characteristic is a copy of the
profile argument specified when the entity is created. You cannot
modify this characteristic.
o receive buffers (OpenVMS)
Default: 4 Value: 1-128
Number of receive buffers reserved for the link. This
characteristic can only be set to a lower value when the entity
is disabled.
o retry maximum
Default: 10 Value: 1-255
Maximum number of times that a frame will be retransmitted before
the local station assumes that a fatal error has occurred. This
characteristic can be modified only when the entity is disabled.
o sequence modulus
Default: 128 Value: 8 or 128
Whether modulo-8 or modulo-128 sequence numbering is allowed
on the HDLC link. The value 8 means that only normal sequence
numbering is allowed. The value 128 means that both extended and
normal sequence numbering are supported for negotiation.