Dac/Tributary Protection - Alcatel-Lucent 9500 MXC User Manual

Chapter 3. 9500 MXC Nodes

DAC/Tributary Protection

Vol. II-3-92
E3/DS3, and STM1/OC3 DACs may be used in pairs to provide hot-standby
redundancy.
The protectable DACs are:
• DAC 3xE3/DS3M
• DAC 1x155o
• DAC 2x155o
• DAC 155oM
• DAC 2x155e
Two protection configurations are supported, tributary protection, and always-on:
Tributary Protection
• Y cables connect the paired DACs to customer equipment.
• In the Rx direction (from the customer) both DACs receive data, but only the
online Rx DAC sends this data to the TDM bus.
• In the Tx direction, the online Tx DAC sends data to customer equipment, the
other mutes its Tx line interface.
Tributary Always On
• Separate cables connect each DAC to customer equipment.
• In the Rx direction (from the customer) both DACs receive data, but only the
online Rx DAC sends this data to the TDM bus.
• In the transmit direction both DACs send data to customer equipment, and the
customer equipment switches between these two
• TA protection must be used where two 9500 MXC INU/INUes are to be
interfaced using protected DACs.
The DACs are configured as primary and secondary. The primary is the default
DAC for online Rx and Tx.
Except for the DAC 155oM, protection switching operates independently for Rx
and Tx, meaning it is possible for one of the DACs to be the online Tx, and the
other online Rx.
When a switching event occurs, all Tx and/or Rx tributaries are switched to the
protection partner. Refer to DAC Protection Switching Criteria on page 3-100.
tributaries.
always on
Alcatel-Lucent