It looks like there is no way to set up working QoS for VOIP phone, at least not using Linksys PAP2T adapter.
Correct me if I am wrong, but SIP travels over UDP ports specified per line, i.e. 5060 and 5061 in my case. I can QoS those.
But actual voice traffic travels over RTP protocol using port range specified per device, which would make it impossible to QoS that port range, as we don’t know which SIP port the RTP ports correspond to.
Basically with the way PAP2T handles VOIP, there is no way to direct one VOIP line’s traffic over one DSL connection, and other VOIP line’s to another.
Hoping I am making sense.