Alcatel-Lucent 9500 MXC, User Manual, Page: 488 / 916

Chapter 8. Protection
Vol. IV-8-6 Alcatel-Lucent
• For a Tributary Protected option (TT selection), the primary DAC is default
online transmitting (Tx to customer equipment) and sending Rx data to the
TDM bus.
• For Tributary Always-On option (TA selection), both primary and
secondary DACs are default online transmitting to customer equipment (the
customer equipment switches between these two always-on tributaries), but
only the primary DAC is sending Rx data to the TDM bus.
• For a TT selection, “Y” cable sets must be used on the tributaries.
• For a TA selection, separate cable sets are used on the tribs to each DAC.
15. LOS on any trib interface is a switching condition. Ensure all traffic-carrying
tribs are commissioned (commissioned tick-box for relevant trib(s) in
Plug-ins screen is ticked). Equally, ensure tribs not used are not
commissioned (not ticked).
16. When a failed hot-standby or diversity RAC/ODU, or failed DAC is repaired
or replaced it immediately becomes available for protection service, but it will
not automatically return to its default configuration for primary and secondary
online operation. Return to default (or other user-configured setup) requires
use of the lock function in the System Controls screen to first force a manual
change, and to then restore Auto/Lock-off.
17. When a failed ring link node is repaired or replaced it is automatically
returned to service after completion of the Error-free Timer period (default 5
minutes) and, if set, the optional Delay Ring Unwrap Timer.
18. A protection guard timer mechanism prevents protection switching
oscillation. Refer to Switching Guard Times on page 3-93, Volume II,
Chapter 3.
Additional Rules for Dual Protection
1. All RACs must be installed in one INUe.
• Four RACs for a protected-with-protected link pairing.
• Three RACs for a protected-with-non-protected link pairing.
2. Subordinated links may use different RACs, for example one link may use
RAC 30s, the other RAC 3Xs. Similarly if a protected link is paired with a
non-protected link, the RAC used in the non-protected link does not need to
be of the same type used in the protected link.
3. Both subordinated links must be configured for the same capacity.
4. Each of the subordinated links are first configured for the protection option
required. Refer to Table 8-1 on page 8-2. Once configured the option to
protect is applied to one of the protected links, whereupon all valid protection
partners are presented for selection.