ZyXEL Communications V501-T1 User Manual
Page 192
Chapter 11 SIP Account Setup
V500 Series User’s Guide
192
Your V500 can add IEEE 802.1Q VLAN ID tags to voice frames that it sends to the network.
This allows the V500 to communicate with a SIP server that is a member of the same VLAN
group. Some ISPs use the VLAN tag to identify voice traffic and give it priority over other
traffic.