Cisco Exam 100-490 Topic 3 Question 53 Discussion

A SmartJack is a type of Network Interface Device (NID) that provides advanced features beyond simple electrical connection. Two of its functions include:

* Regenerating the signal: Similar to a repeater, a SmartJack can buffer and regenerate the signal to compensate for signal degradation that occurs during line transmission. This helps maintain signal integrity over longer distances1.

* Signal conversion: A SmartJack may also provide signal conversion, which involves converting codes and protocols to the type needed by the customer equipment. This can include converting framing types or other signal characteristics to ensure compatibility with the connected devices1.

The other options listed are not primary functions of a SmartJack:

* Operating at Layer 2 of the OSI model is not a function of a SmartJack; it is a characteristic of network devices like switches and bridges.

* Providing channel testing (D) is not a standard function of a SmartJack; however, SmartJacks enable phone companies to remotely test customer wiring without a site visit2.

* Acting as a concentration point for dial-in and dial-out connections (E) is not a function of a SmartJack; this is typically a function of devices like modems or access servers.