The Thor Fiber F-4TEL is used for carrying four phone lines over fiber optic cable. Telephone over Fiber applications offer a secure connection that is impossible to bug. The PSTN two-wire POTS telephone port can be configured either as an FXO (PBX trunk) or FXS (telephone set/fax machine/dial-up modem) device just by a simple DIP switch setting. Using a pair of these devices, four independent telephone lines can be extended over a fiber link. The F-4TEL provides full service for features like caller ID. The converter can be used in service mode, allowing connection of 2 telephone sets. The unit offers SNMP allowing remote management and sensing of converter status, type, version, fiber link status, RJ11 port status, and alarms. The F-4TEL is a simple and reliable solution for data carriers and service providers for Telephone over Fiber links. These devices will carry your RJ11 signal up to 2km on Multimode Fiber and up to 15km on Singlemode Fiber.