Although call quality on VDSL circuits may be currently acceptable, there are no guarantees for current service delivery or future performance. The whitepaper points out that with priority over the public internet given to streaming the explosive growth of digital TV services such as Amazon Prime and Netflix, VDSL VoIP users should expect a deteriorating service. Users wanting to upgrade to Ethernet connectivity for VoIP can be faced with deployment lead times of up to a year for Ethernet circuits causing a crisis.
Graham Lewis, Spitfire's Director IP Engineering and author of the new whitepaper commented, "At Spitfire we discourage the use of VDSL for voice because, whilst anecdotally many people have found it "good enough", it offers no guarantees of voice quality or any route to resolution should voice quality become unacceptable. Our reassurance of an end-to-end service with QoS guarantees has been a key factor in the success of Spitfire SIP trunks for VoIP."
Harry Bowlby, Spitfire's Joint Managing Director commented, "Businesses, who chose a VoIP solution without appropriate QoS guarantees are gambling with their future. Should voice quality issues arise, they may find that an acceptable solution is unavailable or takes an unacceptable period of time to deliver, leaving them unable to receive a business quality telephone service with a consequent materially adverse effect on their trading ability. VoIP over VDSL is a significant potential risk to UK business."
Spitfire only offers customers its own Voice Approved Broadband circuits for VoIP SIP trunks assuring the end-to-end call QoS with guarantees on Latency, Jitter and Delay both upstream and downstream.