Verilink 9000 Series (34-00271) Product Manual - Manual (Page 216)

194 C HAPTER 11: DLP (D ATA L INK P ROTOCOL )
Retransmission Busy Counter
While a remote station is in a busy state, it polls the specified number of times
waiting for the busy condition to clear. If it does not clear after all attempts have
been issued, a failure is detected. The selections are decimal 1 to 255, 10.
Modulo
The modulo type parameter indicates how the information frames are to be
numbered. To use numbers 0 through 7, select Modulo 8. To use numbers 0
through 127, select Modulo 128. The selections are Modulo 8 or Modulo 128.
Window Size
The window size parameter indicates the maximum number of unacknowledged
frames that may exist on a link. The selections are decimal 1 to 7 if Modulo 8 and
1 to 127, 7 if Modulo 128.
T1 Timer
The T1 Timer parameter is the message timeout, in seconds, for messages on the
link. This parameter applies only to primary ports.
Rule 1: T1 prim. > 7 frames
×
No. of characters per frame
×
8
×
Link speed
Rule 2: T1 primary < Device Inop Timer (see Device Inoperational Timer on page 195.)
The selections are decimal 1 to 255, 3.
T2 Timer
The T2 Timer parameter indicates the time, in seconds, that an acknowledge frame
is delayed if there are no data frames, which can carry the acknowledgment, ready
to be sent. In all cases, T2 must be smaller than the other device's T1 timer plus
the propagation time on the line. A value of zero disables the function and an RR
frame is sent on receipt of each data frame. The selections are decimal 0 to 255, 1.
Type of Device
In the X.25 environment, DTE and DCE do not refer to the physical layer but
instead to how the device reacts to different situations. Normally, in an X.25
network, a Packet Assembler/Disassembler (PAD) is a DTE and the Packet Switch
where the PAD is connected is the DCE. When using a communications platform
in a public or private network, the communications platform is normally
configured as a DTE. In a single connection between two communications
platforms, one is configured as DTE and the other as DCE. The selections are
DTE or DCE.