PM7340 S/UNI-IMA-8
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
DATA SHEET
PMC-2001723
ISSUE 3
INVERSE MULTIPLEXING OVER ATM
detected active, the Group state machine will transition into the insufficient links
state and will stop accepting data from the ATM layer for transmission.
10.2.5.5
LASR Procedure
Links will only become active as part of the LASR procedure. The add_group
command will automatically spawn a LASR procedure. To add links or recover
links after group start-up, the Start_LASR command should be used.
If an LASR procedure is in progress, additional Start_LASR commands will be
rejected.
10.2.5.5.1
TX Links
When the LASR procedure starts, all Tx Links (participating in the LASR) in the
unusable state or not_in_group state will immediately transition into the Usable
state if they are not faulted or inhibited. (Note that the FE Rx Links may be
reporting “Not in Group” at this point since their LIDs have not been validated).
Links in other states will remain in the same state. If test patterns are to be
transmitted on the links to test them prior to putting them in service, the Tx links
should be configured to be brought up with the inhibited state set. This keeps the
Tx links in the unusable state until they are released by a new LASR command
(the PM_UNUSABLE status can only be cleared by a LASR).
Once the Tx Links start to report the Usable state, a programmable timer is
started. When either the timer expires or all of the FE Rx links report the active
state, the acceptable Tx Links will transition to the Active state. This completes
the LASR for the TX links.
10.2.5.5.2
Rx Links
During the LASR procedure, the LIDs for the receive links are validated. Until the
LIDS are validated, the RX Links report the “Not in Group” state. As the LIDS are
validated, the Rx Links start to report the unusable state. This transition is not
synchronized with other links in the group.
After all the receive links have their differential delay checked and have no
defects (obtained IMA Frame sync) or a programmable timeout occurs, all of the
accepted links will transition to the usable state.
After the rx links are reported usable, another programmable timeout is started.
Once all of the links are reported TX_Usable by the FE or the timeout expires,
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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