Home Lab (FXS / FXO)

Simulation of FXS and FXO ports are not normally required for home networks because most homes have at least one analog line provided by a Local Exchange Carrier (LEC) or a Voice over IP (VoIP) provider and an analog phone to play with. The analog line provided by your PSTN provider generates dial tone and battery for the devices (analog phones, fax machines, and modems) that plug into it. Instead of plugging this analog line into analog devices, you can connect the RJ-11 port into the FXO (Foreign eXchange Office) of the router. With the proper configuration, you will be able to make and receive calls to the PSTN over the FXO interface. The FXS interface will be connected to an analog phone or fax machine to make and receive phone calls. If you wanted to take the time and go through the trouble associated with it, you could simulate analog connectivity by connecting FXO ports of one router to FXS ports on another router. This functionality will require some advanced knowledge of Private Line Automatic Ringdown (PLAR) and call routing. I recommend using traditional analog phones, fax machines, and PSTN connections because they’re very cheap. At the time of this writing, www.vonage.com offers analog phone services as cheap as $14.99 (US) per month. A lot of students have asked me how to transfer a call directly to voicemail using Cisco’s IP phones. The next blog will discuss how to setup a direct transfer to voicemail using any Call Manager version. We will also discuss the TrnsfVM softkey option available in CUCM. Eventually this conversation will involve the iDivert softkey capability. We’ll also tie IP Manager Assistant (IPMA) into this conversation [re-branded as Cisco Unified Manager Assistant (CUMA)].

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