EPS protects against MPR-e radio, MWA Gigabit Ethernet link, and Packet Microwave Adapter card failures. After the radio frames are processed by the active EPS MPR-e radio, the radio sends the Ethernet traffic down to the 7705 SAR-8 Shelf V2 or 7705 SAR-18. The standby EPS MPR-e radio does not send any Ethernet traffic down to the 7705 SAR-8 Shelf V2 or 7705 SAR-18.
The switching criteria for EPS are:
an MPR-e radio hardware failure
an MWA Gigabit Ethernet link failure between the 7705 SAR-8 Shelf V2 or 7705 SAR-18 and an MPR-e radio
a Packet Microwave Adapter card connected to an active EPS MPR-e going into a missing or failure state