For existing customers, AMS-IX Chicago offers a Closed User Group (CUG) service. The CUG provides the possibility for three or more participants to exchange IP traffic over a dedicated VLAN. This separate VLAN on the AMS-IX Chicago Platform switching infrastructure interconnects the joining parties each with a port on any one of the AMS-IX Chicago switches. The participants can indicate if the CUG VLAN is for dedicated ports only or whether a q-tagged solution (which allows participants to connect to multiple VLANs) is possible. A minimum of three networks should express their interest to participate. Depending on the “charter” of the CUG, participating members must connect using either a dedicated port or an existing port in 802.1Q mode.