Vism Limitations - Cisco MGX 8850 PXM45 Release Notes

Limitations, Restrictions, and Notes
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Manual Clocking
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AXSM
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VISM Limitations

For details on VISM limitations, refer to the Release Notes for Cisco Voice Interworking Service Module
Release 3.1(0). These release notes are available online at the following location:
The release notes are identified by switch name and release number (for example, MGX 8850 (PXM45),
Release 3.0.10.
Release Notes for Cisco MGX 8850 (PXM45), MGX 8850 (PXM1E), and MGX 8830, Software Release 3.0.10
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Currently there is no way for the user to know what is the secondary (second best) clock source in
NCDP mode. This might create problems for the user who is trying to delete/modify the partition
on the line carrying the secondary best clock source.
Revertive option is not provided in NCDP.
AUSM can support only one clock. If a second clock is configured on the same AUSM card AUSM
will send a NACK. When the second clock is sent a NACK, no warning or message is given by the
CLI. The NAK can only be found out by looking through the logs. The second clock configured on
the AUSM will not be reflected in the clocking database.
If the line carrying the primary or the secondary clock source goes in alarm and a switchcc command
is used on the switch, the clock configuration for the line in alarm is removed. The clock
configuration will also be removed if any card is rebooted when the clocking line is in alarm. This
only applies to AXSM and VISMs.
FRSM: NO clock sources supported on FRSM. If a clock source is configured on FRSM it will not
be reflected in our database.
When the resetcd command is used on a service module, the primary and secondary (if configured)
clock sources are recommitted even though the primary or secondary clock source is not a port on
the service module that was reset. Recommitted means that the primary and secondary clock source
will get requalified and the node will temporarily latch onto the internal oscillator, After the clock
is requalified, the node will lock onto the primary clock source once again.
The clock will not revert if the clock switched due to frequency drift.
If ER stamping is used, the rate interval does not provide sufficient accuracy to be completely
effective. As a result, when an AXSM card is supporting a PNNI link which is congested with mixed
CBR/ABR traffic, cells will be dropped. This condition only occurs when ER stamping is enabled
and CI is disabled on an AXSM PNNI link, along with CBR/ABR traffic running so as cause
congestion on the link.
It is recommended that the CI/EFCI mechanism be used for rate feedback rather than the ER
stamping mechanism, especially if CBR/ABR traffic is expected (refer to caveat CSCdw63829).
http://www.cisco.com/univercd/cc/td/doc/product/wanbu/index.htm
OL-2914-01 Rev D0, July 3, 2003