Agilent Technologies Auroraduet N1726A, Руководство пользователя, Страница: 377 / 507

aurora
Duet
- User Guide
8 - 8 422685
aurora
Duet
prevents you from entering a complete address
(LCGN and LCN combined) of 0, since this is reserved
for maintenance/overhead purposes. Thus, for example,
when you enter an LCGN of 0, you cannot set the LCN
to 0.
With the VN4 protocol, you enter the X.25 address using
a single menu option:
LCN/LCGN .
Ø Highlight LCN/LCGN and enter an address between
0 and 4095.
Setting up the D-bit
The ‘D’ Bit is known as the Delivery Confirmation (or
acknowledgement). It indicates whether data packet
reception should be acknowledged locally by the network
(and the data packet passed on to the next stage of the
network on its journey to its final destination) or whether
the final destination should acknowledge the final data
packet.
This allows flow control to be performed either locally or
end-to-end. If the acknowledgement is end-to-end and
there are several stages in the journey, there can be a
significant time delay for acknowledgements when testing
this form of flow control.
Ø Highlight D-BIT and press the LEFT and RIGHT
arrow keys to choose LOCAL or END-TO-END
operation.
2
Notes
• If an incorrect D bit is received, the packet is
discarded; this does not apply to data packets. After
discarding the packet, aurora
Duet
shows the previous
call setup screen whilst waiting for the packet to be
retransmitted.
Chap8s2.PM6 17/06/99, 09:53 8