NOTE: SIP phone is a great option but must be setup by your internal IT team. This is one FastCall feature that is not simple to setup. Adding a SIP phone..
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FastCall support using your existing IP phone as a user phone in click-to-call. The SIP address is added as a user phone in FastCall. Like the softphone, FastCall dials the user on the IP phone directly. Using your existing IP phone is $.01 per minute less with Twilio and tends to be faster than click-to-call.