NS3000/iX NMMGR Screens Reference Manual - Edition 8 (36922-90038)

Chapter 3 41

Link Conﬁguration Screens

Link Conﬁguration: LAP-B Link Data

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