S/UNI-IMA-4 Telecom Standard Product Data Sheet
Released
In order to track the progress of the command interrupts may be enable the LSM state changes
for all of the links. This may result in a large number of events if the group includes a large
number of links.
13.5.8 Reporting Link Defects in the ICP cell
LIF, LODS, and LCD defects are automatically detected and reported in the ICP cell by the
S/UNI-IMA-4. Other physical layer defects such as LOS, OOF, and AIS are not detected by the
S/UNI-IMA-4. To enable reporting of these defects, the Set_rx_defect command is provided to
force the contents of the RDI field in the ICP cell. When the defect bit is set in the command,
this also sets an internal state which prevents the affected LSM’s from progressing towards
active (until the unusable_link command is issued), and immediately terminates any currently
active timers which are waiting on FE state changes for the affected LSM’s. The termination of
these timers (such as RX_link_deleted_timeout, RX_link_blocked_timeout, or
TX_link_deleted_timeout) may result in an immediate NE LSM state change.
13.5.9 Faulting/Inhibiting Links
The S/UNI-IMA-4 reports defects to the upper layer S/W and allows the upper layer S/W
declare fault conditions based upon defect information. In order to force a link into a Fault or
Failure state, the Unusable_Link command is used. This link can operate on multiple links at a
time. Once executed, the LSM of the affected links are transitioned to the Unusable state. If
inhibiting the link without data loss is required, it is necessary to specify the cause as
“inhibited”. Normally when inhibiting a link, the link has been active for a while. If a link is
inhibited immediately after becoming active, data loss can occur. If the S/UNI-IMA-4 has not
yet received ICP cells from the link that indicates the link is active when the link is inhibited,
data loss may occur. Note that links currently experiencing defect conditions will still
experience loss of data even when inhibiting. When links are faulted, the existing data within
the DCB is still played out on the ATM interface.
13.5.10 Change TRL
To change the TRL link, the Update_TRL command is used. The new TRL is immediately used
for scheduling the group and will be reported as the TRL in the next ICP cell. If CTC timing is
used, the stuffing is not affected. If ITC timing is used, the reference link is changed to the new
TRL. The first stuff on the new TRL will occur on approximately the same frame as the stuff
would have occurred when it was a non-reference link. After the first stuff on the new TRL, the
new TRL will be stuffed every 2049 cells.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2020889, Issue 2
285
PMC [ PMC-SIERRA, INC ]
