iConnect625W ADSL/ADSL2+ Router User Guide
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10.6 Modem
Test
The Modem Test feature is used to check the connectivity to the WAN. There are four
test types: F4 End, F4 Seg, F5 End, F5 Seg. Each of these types may take a few
seconds to complete. In order for the test to work, at least one WAN connection must be
configured and a valid DSL link is available. If the DSL link is not connected, the test will
fail.
The OAM (operation, administration and maintenance) loopback cells (F4/F5) are used to
verify the connection between the iConnect625W and the ATM network. For the
iConnect625W, OAM loopback provides a valuable tool for diagnosing problems with the
DSL line. The two main purposes of the F4/F5 cells are:
Fault Management (detection and notification);
Loopback testing and link integrity
The ATM OAM is divided into several levels:
F4: VP Level
o
OAM information flows between network elements (NEs) used within
virtual paths to report an unavailable path or virtual path (VP) that cannot
be guaranteed. Segment flows are processed, as well as end-to-end
flows that terminate in the management processor.
F5: VC Level
o
OAM information flows between network elements (NEs) used within
virtual connections to report degraded virtual channel (VC) performance
such as late arriving cells, lost cells and cell insertion problems.
Segment flows are processed, as well as end-to-end flows that terminate
in the management processor.
Both F4 and F5 flows can be configured as one of the test types:
Segment
o
This test verifies that ATM continuity exists between the virtual channel
link segments from the iConnect625W router to the DSL provider
network (typically this is a DSLAM at the DSL provider site). DSLAM
stands for
Digital Subscriber Line Access Multiplexer.
End-to-End
o
This test verifies ATM continuity exists of the virtual channel link with the
ATM endpoint, such as a remote broadband access router located at the
DSL provider or ISP site.
Before you attempt any of these modem tests, ensure the following:
Your DSL Provider / ISP supports them;
You have a valid DSL link.
To perform a modem test, follow the steps below.
