Link Configuration: LAP-B Link Data [ NS3000/iX NMMGR Screens Reference Manual ] MPE/iX 5.0 Documentation
NS3000/iX NMMGR Screens Reference Manual
Link Configuration: LAP-B Link Data
The Link Configuration: LAP-B Link Data screen (#81)
in figure 3-4 is displayed when you select a link name of type LAP-B at
the Link Selection screen (figure 3-2) and press the [Add] or [Modify]
function key. It is also displayed when you type the path name:
@LINK.linkname
in the command window of any screen and press the [Enter] key, where
linkname is a configured LAP-B link.
Figure 3-4. Link Configuration: LAP-B Link Data
Press the [Save Data] function key to transfer the data displayed on the
screen to the configuration file you are creating or modifying. Verify
that the data record has been created by checking that the Data flag is
set to Y.
Fields
Physical path The physical path of the Programmable Serial
Interface (PSI) card.
The basic formula for deriving the physical
path is 4 x slot number. (Example: 4 x 10 =
40.) For systems with dual card cages, you
must also specify a path number for the card
cage, as follows:
PathNumber/(4 X SlotNumber)
where (a) PathNumber is a number corresponding
to the card cage the PSI is in:
Card cage 0: PathNumber = 2
Card cage 1: PathNumber = 6
(b) / is the slash character (not the division
sign), (c) the parentheses are used to set off
an arithmetic formula ( they are not entered as
part of the Physical Path value), (d) X is the
multiplication sign (not the character X), and
(e) SlotNumber is the number of the slot,
within the card cage, the PSI is in.
Examples:
If the PSI is in card cage 0, slot number 4,
the Physical Path is 2/16
(PathNumber, slash character, 4 multiplied by
4).
If the PSI is in card cage 1, slot number 3,
the Physical Path is 6/12
(PathNumber, slash character, 4 multiplied by
3).
If you are unsure of the slot location or of
the physical path number to configure for your
system, see your system documentation or
consult your Hewlett-Packard service
representative.
Connect timeout (HP modifiable.) During link initialization,
this value specifies the amount of time the PSI
will wait for a response from the remote
station. If this time lapse is exceeded, it is
assumed that the remote station is not
responding.
Default value: 900
Range: 60-900 seconds or 0 (0 means disabled)
Local timeout This is a handshake sequence between the host
and its PSI card. It is useful to prevent the
PSI card from keeping a line up when the system
goes down.
Default value: 60
Range: 30-900 seconds or 0 (0 means disabled)
Modulo count This parameter specifies a window representing
the number of frames that can be outstanding.
Default value: 8
Range: 8 or 128
LAP-B parameter T1 (HP modifiable.) Response timeout in
hundredths of a second. This is the maximum
amount of time that the transmitter should wait
for an acknowledgment before initiating a
recovery procedure. This delay must account
for three frame transmissions and two
frame-processing delays. An approximation of
this value is three seconds for line speeds
greater than or equal to 9600 bits per second
and four seconds for line speeds less than 9600
bits per second.
The formula for the approximation in hundredths
of a second is the following:
400 x [(buffer size x 8)/line speed]
The configuration validation program will issue
a warning if the set value does not comply to
this specification.
Default value: 300
Range: 5 to 1200 hundredths of seconds or 0 (0
means disabled)
LAP-B parameter K (HP modifiable.) This parameter specifies the
maximum number of sequentially numbered
frames that the configured node may have
unacknowledged at any given time. This
parameter is also called the Level 2 window
size.
Default value: 7
Range: 1-7 if modulo count=8; 1-127 if modulo
count=128
LAP-B parameter N2 (HP modifiable.) This field specifies the
maximum number of times to retransmit a frame
if the T1 timer expires. The recovery
procedure mentioned in LAP-B parameter T1
usually refers to the retransmission of the
oldest unacknowledged frame. The value of N2
specifies the total number of times that the T1
timer expires and a frame is retransmitted in
determining that the other side is not
responding.
Default value: 20
Range: 1-255 retries
Buffer size Layer 3 through 7 frame size. This is the
amount of data that a user of OSI Levels 3
through 7 can put in that frame. It does not
include Level 2 header or trailer information.
This parameter is used to configure memory
buffers.
Default value: 1024
Range: 32-1024 Bytes
Local mode If the node you are configuring is a
Hewlett-Packard computer operating across a
point-to-point link, enter 11 (the default).
HP computers at both ends of a point-to-point
link must both be configured as HP
point-to-point. If the remote node is a non-HP
node and the local station is acting as DTE,
enter 5. If the remote node is a non-HP node
and the local station is acting as DCE, enter
6. If the node you are configuring is DCE,
then the node at the other side must be DTE. If
the node you are configuring is DTE, then the
node at the other side must be DCE.
Default value: 11
Range: 5 =DTE
6 =DCE
11 =HP Point-to-Point
Transmission speed This is the line-transmission speed in bits per
second. It may be overridden by whichever
device is providing clocking. The PSI simply
transmits using the provided clock source,
whether it is the HP 3000's CPU clock or a
modem.
Default value: 56000
Range: 1200, 2400, 4800, 9600, 19200, 38400,
56000, or 64000 bits/second
Trace at startup (HP modifiable.) Enter Y (YES) to enable link
tracing at link startup, N (NO) otherwise.
This value can be overridden with the
LINKCONTROL command.If you do enable link
tracing, you are required to enter a trace file
name.
For best performance, do not enable tracing.
Default value: N
Trace file name (HP modifiable.) Required if link trace is
enabled. Name of the disk file where you want
to record tracing. Must be a valid file
name. Enter the file name in the format
filename.groupname.acctname. The fully
qualified file name can be as many as 26
characters.
Lockwords are not allowed for trace files.
Do not specify the same file name with the
NMMGR configuration as specified with the
LINKCONTROL command.Only one active trace is
allowed per link.
MPE/iX 5.0 Documentation