VoiceGuard™ Client SDK	VPN	VoipTunnel (VPS)
Voice Quality (MOS)	≥4.0	<4.0	about 4.0
Overhead	minimal	huge	general
Plug & Play	yes	no	yes
ISP Detection	more difficult	difficult	easy
Recurring Payment	no	yes	no
Interoperable with 3rd-party Sip Proxy	yes	yes	VPS only
Packet Forwarding Performance	high	low	moderate