The document discusses configuring single-tag VLAN mapping on Huawei S5700 switches to allow communication between client devices in different VLANs. It involves creating VLANs 10, 20 and 100 on switches, adding ports to the VLANs, and configuring single-tag VLAN mapping on trunk ports between switches to map VLANs 10 and 20 to VLAN 100 to allow inter-VLAN communication. The configuration is verified by pinging from a client in VLAN 10 to a client in VLAN 20 to confirm connectivity across the VLANs.