Most companies that plan on replacing legacy digital phone sets with IP phones should first focus on upgrading their infrastructure. Why replace legacy digital handsets when a SIP gateway can emulate the digital hard phone as a SIP endpoint? A SIP phone gateway would take an existing digital hand set and convert the signaling to SIP and pass the media. Transcoding, media forking, status, and other IP phone functionality would also occur. The corporate hard phone should deliver basic phone functionality and a quality audio stream. The gateway will allow an enterprise to reap the benefits of an IP phone without having to make the full investment in swapping phones. Such benefits include:
* Software based MACDs * Presence indication when someone is on the phone * Mobility--Single number, multi-phone ringing, real time call transfers
This technology does not make sense on new real estate moves and having to run the parallel wiring required for digital phones. But, for existing buildings wired for phones with a legacy PBX and phones, there is an option to delay the investment required to upgrade to IP phones. That money in turn can be used for SIP Trunking to lower Telecom expenses, build a SIP infrastructure to integrate legacy systems with new SIP applications, and add new UC features that will help a business grow top line revenue.
In the evolution from legacy PBX systems to VoIP, the hard phone should be the last portion of the migration, not the first. The digital phone is dead, long live the digital phone.