
Stinger®
SHDSL 48-Port and 72-Port Line Interface Modules (LIM) Guide
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Configuring LIM and LIM Port
Redundancy
You can configure LIM and LIM port redundancy for more than one kind of LIM in a
single Stinger chassis. For example, a single Stinger unit with both asymmetric digital
subscriber line (ADSL) and symmetric digital subscriber line (SDSL) LIMs can be
configured with a spare ADSL LIM and a spare SDSL LIM.
Overview of LIM and LIM port redundancy
A spare LIM can replace an entire failed LIM or a single failed port. LIM redundancy
transfers all logical connections from a failed LIM to the spare LIM. LIM port
redundancy transfers the logical connection from a particular failed port on a LIM to
the corresponding port on the spare LIM. The remaining ports on the spare LIM
remain available to provide additional LIM port redundancy.
Each LIM to be used as a spare must have either a path selector module (PSM) or
copper loop test (CLT) module plugged in behind or next to it in place of a line
protection module (LPM). All other LIMs must use an LPM with port redundancy
(LPM-PR) for line protection.
Note
Some older Stinger units are equipped with an interface redundancy module
(IRM) located behind the spare LIM, and LPMs with redundancy (LPM-R) located
behind the LIMs to be backed up. In this case, additional configuration steps might be
needed. For more information, see “LIM redundancy with IRMs and LPM-Rs” on
page 2-6.
Configuring LIM redundancy
LIM redundancy provides a one-to-one backup function for LIMs. Each type of LIM
to be backed up requires a spare LIM with a PSM or CLT module plugged in behind or
next to it. For example, a Stinger FS unit configured with 14 ADSL 24-port LIMs can
be set up with the following module pairs:
■
13 pairs each consisting of an ADSL LIM and an LPM-RP
■
1 pair consisting of an ADSL LIM and a PSM or CLT module
Overview of LIM and LIM port redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1