The DDCMP link entity defines the attributes of a link to a communications port that uses the DDCMP protocol.
1 – character
DEAD TIMER
Default: 10000 Value: 1-65535
Specifies the delay, in milliseconds, between polls of one of the set
of dead tributaries. This attribute is supported only if the
characteristic protocol is set to control.
DELAY TIMER
Default: 0 Value: 0-65535
Specifies the minimum delay, in milliseconds, between polls. You can
use this timer to limit the effect of a fast control station on slower
tributaries. A value of 0 means that no delay is added. This attribute
is supported only if the characteristic protocol is set to control.
PHYSICAL LINE
Default: No Name Value: local-entity-name
Name of the Physical layer entity that the link operates over. A value
for this characteristic must be set before the link entity is enabled.
You can modify this characteristic only when the entity is disabled.
PROTOCOL
Default: Point
Protocol mode used by the local station. You cannot modify this
characteristic. The value of this characteristic is a copy of the
protocol argument specified when the DDCMP link entity is created.
The default value is point and is the only permissible value.
RECEIVE BUFFERS
Default: 4 Value: 1-255
Number of receive buffers reserved for the link. You can modify this
characteristic only when the entity is disabled. Also, you can only
increase the characteristic value.
RETRANSMIT TIMER
Default: 3000 Value: 1-65535
Maximum time, in milliseconds, to wait between sending a message and
receiving a valid response. If this time expires, the local station
takes error recovery action. On full-duplex point-to-point links, the
timer is started immediately when a message is sent.
SCHEDULING TIMER
Default: 200 Value: 50-65535
Time, in milliseconds, between the recalculation of tributary polling
priorities. This attribute is supported only if the characteristic
protocol is set to control.
STREAM TIMER
Default: 6000 Value: 0-65535
Time, in milliseconds, for which a tributary or the remote station on
a half-duplex, point-to-point link can hold the line. This
characteristic is not supported if the characteristic protocol is
set to tributary.
2 – counters
NAKS RECEIVED INDICATING MESSAGE HEADER FORMAT ERROR
Number of NAK messages received that report errors in message headers
sent from the local station.
NAKS RECEIVED INDICATING RECEIVE OVERRUN
Number of NAK messages received that report a receive overrun at the
remote station.
PDUS RECEIVED WITH MESSAGE HEADER FORMAT ERROR
Number of times the local station detected an error in a message
header.
RECEIVE OVERRUNS
Number of times the local station detected a receive overrun.
SELECTION ADDRESS ERRORS
Number of times that the controller of a multipoint link received a
message with an address other than that of the currently selected
station. This counter is supported only if the characteristic protocol
is set to control.
STREAMING TRIBUTARIES
Number of times that the remote station or a tributary station
exceeded the maximum transmission interval without releasing the line,
or failed to release the line after sending a message with the select
flag set. This counter is present only on half-duplex, point-to-point
links, or when the local station is a controller of a multipoint link.
This counter is not supported if the protocol characteristic is set
to tributary.
TRANSMIT UNDERRUNS
Number of times the local station detected a transmit underrun.
3 – status
PHYSICAL PORT
Name of the port entity in the Physical layer returned when the port
is opened. If this is null, the port is not open.
STATE
State of the DDCMP link. The value of this attribute is determined by
the enable and disable commands.
OFF - The entity is disabled.
ON - The entity is enabled.
In addition the link is disabled and its state set to off if the
Physical layer port that the link uses is deleted.