The ZPHA device receives power through the USB connection to the IPS. If the USB power connection to the IPS is interrupted by a power supply failure, power loss, or unplugging, the ZPHA instantly switches to route network traffic, bypassing the IPS connections. It provides two USB ports for connecting two IPS devices. In addition, the ZPHA chassis may be daisy-chained by connecting them through their USB ports.

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The ZPHA bypass system comes in two different models;

• Fixed ZPHA chassis, five segments (copper only), two USB-B type ports
• Modular ZPHA chassis, five segments (copper/fiber), one each USB-A/USB-B type ports

Modular ZPHA chassis daisy-chaining

In order to protect more than five IPS segments, two separate ZPHA bypass chassis have to be utilized. The issue with this configuration is that the ZPHA bypass chassis utilizes the USB power available from the IPS device and due to the energy consumption of the ZPHA modules, a specific configuration has to be enabled if a combination of copper and fiber ports is being configured between the IPS and the multiple ZPHA chassis.

The options available for ZPHA daisy-chaining are as follows;

Option 1: Both ZPHA systems are Modular with a combination of copper and fiber ports.

• USB cable, A/B connection between IPS and Modular ZPHA.
• USB cable, A/B connection between both Modular ZPHA systems.

Option 2: Fixed ZPHA (copper only) with a Modular ZPHA system and a combination of copper and fiber ports.

• USB cable, A/B connection between IPS and Modular ZPHA.
• USB cable, A/B connection between Modular ZPHA and Fixed ZPHA (copper only).

Option 3: Both ZPHA systems are Fixed ZPHA (copper only).

• USB cable, A/B connection between IPS and first ZPHA.
• USB cable, B/B connection between first ZPHA and second ZPHA.

Option 4: Both Modular ZPHA with all copper modules.

• USB cable A/B connection between IPS and first ZPHA.
• USB cable B/B connection between first ZPHA and second ZPHA.