Westell VersaLink 7550 (B90-755025-15)

Overview
This device is a Westell 7550 (Netgear).
 * It was used with AT&T's DSL service.

"RTA4515W-D27(RoHS)" is silkscreened on the board.
 * FCC photos show a USB port, but on hand example does not have it populated.

Per this router UI screenshot, this device uses an Atheros wireless chip.
 * CPU: Lantiq XWAY ARX168 (PSB 50810 EL V1.2) @333MHz
 * Switch: Lantiq XWAY TANTOS (PSB 6970 V V1.3)