In the early days, when VoIP was still in its infancy, businesses large and small were reluctant to transition off of their tried and true TDM Networks to bleeding edge IP Telephony. If it ain't broke don't fix it was the mantra heard at industry events, along with murmurs about unpredictable call quality and other horror stories, compared to TDM's unmatched clarity and reliability. But the advantages of IP Telephony were far to great to resist. It the end, it was codecs like G.729, (and its siblings - G.729a/b), that rode in and helped aid in the rapid adoption of VoIP over next decade or so. Well, thank you so much G.729! Now slide over and let an HD codec take the wheel.