
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7341 S/UNI-IMA-84
DATASHEET
PMC-2000223
ISSUE 4
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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RDAT to indicate the LIDs to include in the round robin. The IDCC will only
change its rate at IMA frame boundaries.
10.2.6 Support of IMA Test Pattern Procedure
S/UNI-IMA-84 supports the IMA test pattern procedure in both the TX direction
(NE initiated) and RX direction (FE initiated).
In the TX direction, the S/UNI-IMA-84 updates the TX test control info and TX
test pattern field in the outgoing ICP cells, as prompted by the relevant
Update_test_ptn command. Meanwhile, the S/UNI-IMA-84 will always compare
the RX test pattern field received in the incoming ICP cells with the TX test
pattern value being transmitted, and save the result on a per-link basis in the
group context memory.
In the RX direction, the S/UNI-IMA-84 always analyzes the TX test control info
field in the incoming ICP cells. If the test link command field is set to “active”, the
TX test pattern field in the incoming ICP cells on the selected link will be copied
to the RX test pattern field in the outgoing ICP cells. Otherwise the RX test
pattern field in the outgoing ICP cells will be filled with “0xFF”.
10.2.7 Support of Symmetric/Asymmetric Operation Modes
S/UNI-IMA-84 supports all three possible group symmetry modes: symmetric
configuration and symmetric operation; symmetric configuration and asymmetric
operation; asymmetric configuration and asymmetric operation.
For symmetric configuration, the number of TX and RX links in the group must be
the same; for asymmetric configuration, that restriction does not apply.
The support for asymmetric/symmetric operation modes is part of the S/UNI-IMA
functionality. The symmetric operation mode is treated as a special case of the
asymmetric operation, where the TX and RX LSM on the same physical link are
inter-dependent.
10.2.8 Support of Different IMA Versions
It should be noted that the technique used to report RX information over the Link
Information fields in the ICP cells when the group is configured in the symmetrical
configuration and operation mode differs in the IMA v1.1 implementations and the
IMA v1.0 implementations.