HP 3000 Manuals HP 3000 Manuals
NS3000/iX LAP-B Link Statistics
The following section describes the data that is output when you issue
the LINKCONTROL command to obtain statistics relating to NS3000/iX LAP-B
Links.
LINKSTATE Parameter Fields
Figure A-1 provides an example of the data that is displayed when you
issue the LINKCONTROL linkname;STATUS=LINKSTATE command:
Linkname: LAPB20 Linktype: LAPB Linkstate: CONNECTED LEVEL 2
Figure A-1. LINKSTATE Command for LAP-B Link
Linkname. The Linkname field specifies the name of the link.
Linktype. This Linktype specifies the type of link, such as LAP-B or
IEEE 802.3, that is being monitored.
Linkstate. The Linkstate field specifies the current state of the link.
The possible link states are as follows:
* Not connected.
* Connected level 1.
* Connected level 2.
* Connecting level 1.
* Connecting level 2.
* Disconnecting level 1.
* Disconnecting level 2.
In this example, in figure A-1, the current state of the LAPB link named
LAPB20 is CONNECTED LEVEL 2.
The LINKSTATE parameter fields are displayed whenever you enter the
LINKCONTROL Status command, regardless of which other parameters are
specified.
CONFIGURATION Parameter Fields
The CONFIGURATION parameter for LAP-B links displays the LINKSTATE
parameter fields and many additional fields. These additional fields
display information that is related to the link configuration and which,
except for the Cable Type parameter, are input through the NMMGR
configuration program.
Figure A-2 provides an example of the data that is displayed when you
issue the LINKCONTROL linkname;STATUS=CONFIGURATION command:
Physical Path 24
Phone Number 9D1D40898765432
Modulo Count 8 Cable Type RS232
Local Mode HP-HP Buffer Size 1024 Bytes
LAPB Parm K 7 Connect Timeout 60 sec
LAPB Parm T1 300 hsec Local Timeout 900 sec
LAPB Parm N2 20 Transmission Speed 64000 bps
Figure A-2. LAP-B CONFIGURATION Parameter Output
Physical Path. The Physical Path field displays the current physical
path of the PSI card as specified in the NMMGR configuration file.
Phone Number. The Phone Number field displays the current automatic dial
phone number, as specified in the NMMGR configuration file.
Modulo Count. The Modulo Count field displays the maximum frame sequence
number allowable for any frame in the network. This field can be set to
a value of 8 or 128, meaning that frames are numbered from either 0
through 7, or 0 through 127.
Cable Type. The Cable Type field displays the cable type that is
currently connected to the PSI card. This data is provided by the PSI
card and cannot be configured through NMMGR. The possible values for this
field are as follows:
* RS232.
* V35.
* Modem Eliminator.
* RS366.
* RS449.
* Loopback.
* None.
Local Mode. The Local Mode field displays the value specified for local
mode in the NMMGR link screen. The possible values for this field are as
follows:
* HP-HP, for connection to another HP device configured as HP
Point-to-Point.
* DTE, for connection to a device that is configured as a DCE.
* DCE, for connection to a device that is configured as a DTE.
Buffer Size. The Buffer Size field displays the current buffer size.
This value will be equal to the buffer size configured in the NMMGR Link
screen plus 4 bytes of overhead that is added by the level 3 protocol.
LAPB Parm K. The LAPB Parm K field displays the configured number of
unacknowledged frames that are allowed in the network at any given time.
For example, if this value is set to seven (7) for a node, and that node
transmits seven (7) packet frames onto the network, it cannot transmit
another frame until one or more of the transmitted frames are
acknowledged.
Connect Timeout. The Connect Timeout field displays the current logical
link level 2 connection timeout. The Connect Timeout parameter sets the
amount of time a node will wait for a logical connection to a remote node
to be established. If this timer expires, the node aborts the connection
attempt. The abort process can take several additional seconds.
LAPB Parm T1. The LAPB Parm T1 field displays the current value
of the T1 timer. The T1 timer waits the specified number of
hundredths-of-seconds for a particular frame to be acknowledged. A frame
that is transmitted, but not acknowledged, before the T1 timer expires,
is retransmitted.
Local Timeout. The Local Timeout field displays the value specified for
the Local timer. This timer, also called a heartbeat timer, is used to
monitor whether the system and/or the PSI card are functioning. The PSI
card, and the system, transmit a signal, called a heartbeat signal, to
each other on a specified schedule. If, for example, the heartbeat does
not arrive at the PSI card from the system (or vice-versa), the card or
system waits the number of seconds specified by this field. If no
heartbeat arrives before this timer expires, the link is dropped. You
can determine whether the PSI card or the system failed by checking to
see which device is still active. The default for this field is 60
seconds and it is recommended that you do not change the value of this
field. The PSI always waits 20 seconds longer than the system waits
before it drops the link.
LAPB Parm N2. The LAPB Parm N2 field displays the maximum number of
times a frame is retransmitted after the LAPB Parm T1 expires. The frame
is retransmitted at the LAPB Parm T1 interval for the number of times
specified in this field. When this count is depleted, the frame is
retransmitted at 20 second intervals. If no response is received after
these transmissions, the link is brought down.
A node that is configured with the value specified in figure A-2 will
attempt to retransmit an unacknowledged frame a maximum of 20 times at T1
intervals.
Transmission Speed. The Transmission Speed field displays the current
transfer rate, or clocking, configured for the node in the NMMGR Link
screen. If modems are used, the modems will control the clocking. The
PSI card transmits at the clocking setting of the modem and ignores the
value configured in this field.
STATISTICS Parameter Fields
The STATISTICS parameter for LAP-B links displays many fields in addition
to the LINKSTATE parameter fields. The CONFIGURATION parameter fields
are not displayed with this parameter. Figure A-3 is an example
of the data that is displayed when you issue the LINKCONTROL
linkname;STATUS=STATISTICS command:
Connection Duration 23:25:01 Tracing OFF
Data Bytes Sent 62650 Data Bytes Received 62300
Overhead Bytes Sent 8592 Overhead Bytes Received 8550
Total Frames Sent 1430 Total Frames Received 1425
Data Frames Sent 1253 Data Frames Received 1246
Aborted Frames Sent 62650 Aborted Received 0
DSR Losses 0 Oversized Frames Received 0
CTS Carrier Losses 0 Receive Overruns 0
DED Carrier Losses 0 CRC Errors 0
Statistics Resets 0
Figure A-3. LAP-B STATISTICS Parameter Output
Connect Duration. The Connect Duration field displays the length of time
that the current logical (level 2) connection has existed. If there is
no active connection, this field displays the length of time that the
most recently established connection was in existence. This field is
reset with each new connection.
Tracing. The Tracing field specifies whether tracing is currently
enabled or disabled.
Data Bytes Sent. The Data Bytes Sent field displays the number of bytes
that have been transmitted in the data portion of all data frames.
Data Bytes Received. The Data Bytes Received field displays the number
of bytes that have been received in the data portion of all data frames.
Overhead Bytes Sent. The Overhead Bytes Sent field displays the total
number of flags, level 2 address and control bytes, and frame check
sequence (FCS) bytes transmitted. This value should be equal to six
times the total number of frames transmitted.
Overhead Bytes Received. The Overhead Bytes Received field displays the
total number of flags, level 2 address and control bytes, and FCS bytes
received. This value should be equal to six times the total number of
frames transmitted.
Total Frames Sent. The Total Frames Sent field displays the total number
of frames transmitted.
Total Frames Received. The Total Frames Received field displays the
total number of frames received.
Data Frames Sent. The Data Frames Sent field displays the total number
of transmitted data frames.
Data Frames Received. The Data Frames Received field displays the total
number of received data frames.
Aborted Frames Sent. The Aborted Frames Sent field displays the number
of frames which were aborted before they were received. Normally, this
number should be quite low (below 3% of the total number of frames sent).
A large number could point to a noisy line or a weak or bad clock signal
sent by a modem. If this value becomes larger than 3% of the total
number of frames sent, and you feel that network performance is being
affected, contact your HP representative.
Aborted Frames Received. The Aborted Frames Received field displays the
number of frames which were aborted after they were received. Normally,
this number should be quite low (below 3% of the total number of frames
received). A large number could point to a noisy line or a weak or bad
clock signal sent by a modem. If this value becomes larger than 3% of
the total number of frames received, and you feel that network
performance is being affected, contact your HP representative.
DSR Losses. The DSR Losses field displays the number of times the PSI
detected a temporary loss of the Data Set Ready (DSR) signal on the
cable. On most lines, this will remain at a value of zero, although some
modems will periodically drop signals for very short intervals.
Oversized Frames Received. The Oversized Frames Received field displays
the number of frames received that exceed the maximum configured buffer
size as configured in the Link screen of NMMGR. A number other than zero
in this field indicates that the remote buffer size configuration is
greater than the local buffer size configuration. One or both
configurations must be modified so that the two buffer sizes are
identical.
CTS Carrier Losses. The CTS Carrier Losses field displays the number of
times the PSI detected a temporary loss of the Clear to Send (CTS) signal
on the cable. On most lines, this will remain at a value of zero,
although some modems will periodically drop signals for very short
intervals.
Receive Overruns. The Receive Overruns field displays the number of
times that the PSI card had to discard a frame because the PSI card could
not process the data as quickly as it arrived. A number in this field
that is greater than 3% of the total number of received frames indicates
a possible problem with the PSI card. If this number continues to
increase, contact your HP representative.
DCD Carrier Losses. The DCD Carrier Losses field displays the number of
times the PSI detected a temporary loss of the Data Carrier Detect (DCD)
signal on the cable. On most lines, this will remain at a value of zero,
although some modems will periodically drop signals for very short
intervals.iDCD carrier losses
CRC Errors. The CRC Errors field displays the number of frames that were
received with a bad Cyclic Redundancy Check (CRC) checksum. A large
number (greater than 1% of the total number of packets) indicates that a
problem may exist in the connection between the PSI and the modem, or
between the two modems.
Statistics Resets. The Statistics Resets field displays the number of
times that the statistics buffer (which contains the values for all of
the aforementioned fields) was reset. This value is reset each time the
link is restarted.
RESET Parameter Fields
The RESET parameter for LAP-B links resets all of the accumulated
statistics for the links. This command also displays all of the
LINKSTATE, CONFIGURATION, and STATISTICS parameter fields. Refer to the
STATISTICS parameter for a description of the displayed fields.
ALL Parameter Fields
The ALL parameter for LAP-B links displays all of the LINKSTATE,
CONFIGURATION, and STATISTICS parameter fields. Figure A-4 is an example
of the ALL parameter output:
Linkname: LAPB20 Linktype: LAPB Linkstate: CONNECTED LEVEL 2
Physical Path 24
Phone Number 9D1D40898765432
Modulo Count 8 Cable Type RS232
Local Mode HP-HP Buffer Size 1024 Bytes
LAPB Parm K 7 Connect Timeout 60 sec
LAPB Parm T1 300 hsec Local Timeout 900 sec
LAPB Parm N2 20 Transmission Speed 64000 bps
Connection Duration 23:25:01 Tracing OFF
Data Bytes Sent 62650 Data Bytes Received 62300
Overhead Bytes Sent 8592 Overhead Bytes Received 8550
Total Frames Sent 1430 Total Frames Received 1425
Data Frames Sent 1253 Data Frames Received 1246
Aborted Frames Sent 62650 Aborted Received 0
DSR Losses 0 Oversized Frames Received 0
CTS Carrier Losses 0 Receive Overruns 0
DED Carrier Losses 0 CRC Errors 0
Statistics Resets 0
Figure A-4. LAP-B ALL Parameter Output