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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
110
the accepted links will start to report RX_Active. If operating in symmetrical
mode, the TE Tx links must be in the usable/Active state in order for the accepted
links to transition into RX_Active. If some additional links have become usable
since the last timeout, they will skip directly from the unusable to the active state.
This completes the LASR for the Rx Links. When the LASR for both the RX and
TX links is complete, the LASR procedure is complete. If the LASR completes
due to a timeout and not all of the links are in the active state, an interrupt will be
generated (if enabled) to inform PM that the links were not brought to the active
state.
10.2.5.6
Deactivating Links
Links may be brought down by either PM or by the far end. PM may declare a
fault on a link, inhibit a link, or delete the link. The Far-end state changes may
also cause the link to go down. This is the method of coordinating link
deactivation between the NE and FE.
10.2.5.6.1
Far End link deactivation
If the FE Tx states transition into an unusable state, the NE Rx states go to the
usable state and all data received prior to this point will be played out.
If the FE Rx states transition into a not active state, the NE Tx link will transition
into the usable state and stop transmitting data on that link.
10.2.5.6.2
Near End (management) link deactivation
If the NE Rx link is removed from the group, the S/UNI-IMA-84 will transition to
the deleted state until all previously received data is played out to the ATM layer;
at which point, it will deactivate itself and be removed from the round-robin.
In absence of defects, the S/UNI-IMA-84 will bring down the link without loss of
data.
10.2.5.7
Rate Changes
When the RIPP changes the state of a link to active, it programs the appropriate
IDCC scheduler with the new rate. This is done by providing a vector that
identifies the active LIDs for the group. This vector is used to determine the
number of links for the rate calculation and is then passed on to the TIMA or