Netrounds supports both untagged and tagged interfaces on Test Agents (except on Test Agents Lite). VLAN tagging is defined in the IEEE 802.1Q standard. A Test Agent can have 20 simultaneous VLANs defined for each physical interface.
For Ethernet activation tests, Netrounds supports VLAN stacking (QinQ) according to the IEEE 802.1ad standard. It is not possible to generate synthetic traffic (UDP and TCP) using VLAN stacking.