ABB EDS500 Series, Руководство по эксплуатации функций

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DSL Interfaces Functions
negotiation that is further away or cannot be reached as easily. Like that in case of an error
the option to set the reachable side to a lower data rate to re-establish the line.
For an estimation of the achievable data rate at a given distance refer to Chapter 2.15.6,
"Signal Quality, Line Length and Data Rate"
ADVICE
Setting a DSL data rate interrupts the connection and starts a new negotiation. Special
care has to be taken if the configuration of the corresponding line is carried out by oneself.
The default value for speed of the interface dsl1 is 192 kbps.
The default value for speed of the interface dsl2 is auto.
Commands to configure the data rate of DSL interfaces
< s e t i n t e r f a c e { d s l 1 | d s l 2 } s p e e d { { 1 9 2 - 1 5 0 0 0 } | a u t o |
e x t - a u t o } >
ADVICE
If compatible data rates have not been set on both sides of the DSL line, a connection
establishment can happen (if possible on that line). This causes the alarm Speed mismatch
(Alarm LED flashes, DSL Alarm LED permanently lit) (refer to Chapter 2.12, "Alarms and
Alarm Configuration").
2.15.4 Termination of Link in Case of an Error
Depending on the application scenario it can be desirable to interrupt the logical interface
connection as quickly as possible when there is an interrupted or intermittently errored
transmission line or to keep it as long as possible during a perhaps only temporary
interruption.
The error rate of DSL interfaces is monitored by the system. If it reaches a threshold that
is dynamically adapted to the transmission rate then the connection is terminated and re-
established. The threshold can be set with a command.
Setting Description
fast This setting detect a line interruption within a few milliseconds but there is
the danger that the connection has to be interrupted and re-established due
to very shortlived interferences. For a quick convergence of a redundancy pro-
tocol like Spanning Tree it is important that the information on link failures is
recorded as quickly as possible. On the other hand it may not be desirable that
a failure in the range of milliseconds causes a convergence process that poten-
tially takes a couple of seconds.
slow This sets an error threshold to a high value, so that the link becomes more tol-
erant to interferences and a short disruption does not lead to terminate the
connection. However, the detection of a cable failure (line interruption) takes
longer, up to a maximum of 6 seconds. Logically, the line appears to be OK dur-
ing this time. This setting can be sensible in periodically errored environments
if it is desirable that the connection does not fail regularly.
medium This is the default and should represent the best compromise for most trans-
mission lines between robustness of the connection on the one hand and
detecting a cable fault on the other hand.
Table 18: Settings to terminate a DSL connection
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