... DNS SRV Voice Transport RTP/RTCP, Real-Time Transfer Protocol / Real-Time Transport Control Protocol QoS IP ToS & DSCP Diffserv Tagging, RFC2474 ... Managed SNMP V1/V2, TR-069 & TR-104 Syslog Protocol RFC5424. Syslog level: DEBUG, NOTICE, WARNING, ERROR SERVICE ... ). Color Ring Back Tone Customizable Standard Services Caller ID, Call Transfer, Call Hold, Call Forward, Call Waiting, Change Caller ID ...