Lucent Technologies 6000 - Manual (Page 290)

6-4 MAX 6000/3000 Network Configuration Guide
Configuring X.25
Configuring the logical link to an X.25 network
The next set of parameters in Ethernet > X.25 > X.25 profile includes defining the maximum
number of seconds before recovery procedures begin, how many times the MAX can resend
frames when the timer expires, and the maximum number of sequentially numbered frames
that can be unacknowledged:
X.25 profile parameters
The next set of parameters in Ethernet > X.25 > X.25 profile includes defining features on a
X.25 connection, such as the minimum and maximum X.25 packet size to the duration of
timers to receive or send X.25 packets:
Parameter Specifies
LAPB T1 Maximum number of seconds the transmitter waits for
acknowledgment before initiating a recovery procedure (Response
timeout). The default is 3 seconds.
LAPB N2 How many times the MAX can resend a frame when the LAPB T1
timer expires. The default is 20. This relatively high value increases the
probability of a correct transfer of data.
LAPB k Maximum number of sequentially numbered frames that can be
unacknowledged at a given time. This value is also called the Level 2
Window Size or the Frame Window Size. The default is 7. Higher
values enable faster throughput.
Parameter Specifies
X.25 Seq Number
Mode The number of frames a sender can transmit before requiring an
acknowledgment of the first frame. The protocol increments a
sequence number in the frame header, and places the value into the
next outgoing frame. The sequence number identifies each frame that
has not yet been acknowledged.
X.25 Link Setup
Mode Whether or not the X.25 link comes up in active- or passive-
disconnect mode. In active-disconnect mode (the default), the link
layer sends a DISC, and the packet layer sends a Restart-Request
packet, upon initialization. In passive-disconnect mode, the link layer
sends SABM(E) upon initialization and issues a restart to the network
only upon receipt of a Restart-Request packet. It does not issue a
Restart-Request packet upon initialization, but responds to Restart
packets it receives.
X.25 Node Type Whether or not the MAX interacts with the remote end of the
connection as a DTE (the default) or a DCE (when emulating the X.25
network). Data Terminal Equipment (DTE) is a device that an operator
uses, such as a computer or a terminal. Data Circuit-Terminating
Equipment (DCE) is a device that connects the DTE to a
communications channel.
X.25 window size The default for maximum number of outstanding data packets that can
accumulate before the MAX requires an acknowledgment. The default
is 2.