Cabletron Systems Netlink FRX8000, User Manual

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Configuring Inter-Nodal Trunks 7-15
increases the probability of an eventual correct transfer between DTE and DCE, but a
smaller value permits faster detection of a permanent error condition.
T1 Retransmission Period
is X.25 timer T1, the length of time before the node will transmit an I-frame if the pre-
vious transmission is not acknowledged. If the period expires, the timer will be reset
and a supervisory frame will be transmitted demanding immediate acknowledgment.
The N2 (see that entry) counter will also be incremented.
The default value of 2000 ms allows avoidance of unnecessary retransmission of
frames that have merely been delayed.
T2 Acknowledgment Delay
is X.25 timer T2, the length of time the node will delay acknowledgment of a received
I-frame if there is no outgoing I-frame to be sent. If during this period the node
receives an I-frame for transmission, the acknowledgment will be sent with it, and the
delay timer will be reset.
T3 Link Assurance Period
is X.25 timer T3, the length of time after which the logical DCE will poll its coun-
terpart if there is no data transfer. The value should be sufficiently larger than the
DCE's T1 timer (Retransmission Period), to assure that the link is not operational
before a poll is sent.
Maximum Packet Size
is the maximum data packet size that will be allowed to pass through this port. A
packet size included in a call setup packet will be used, as long as it is smaller than the
maximum specified here.
Logical DCE
Selecting
N
defines the port as logical DTE. The other end of the connection must be
the opposite of this port. Logical DCE/DTE is independent of physical—either can be
either. A node connecting a subscriber device into a network should normally be con-
figured as logical DCE.
Generate Clock
If this port is a physical DCE (determined by LP jumpers and/or cable/converter
interface), specify
Y
, since DCE generates clock. If the port is DTE, specify
N
.
Rcv Clock (TT) from DTE
allows the clock to be looped back from the DTE using the TT (Terminal Timing)
signal, which can be helpful on high-speed ports.
Mask Link Alarms
determines whether an alarm will be generated if the link goes up or down. If
Mask
Link Alarms
is
Y
, these alarms will not be generated.
Propagation Delay
tells the software how long it will take a signal to travel from one point to another
(e.g., from a satellite dish to a satellite). This helps the FRX8000 determine the fastest
routing. The value to be specified is normally determined by the signal carrier.