Methods, apparatus, and products are disclosed for forwarding frames in a computer network using shortest path bridging (‘SPB’). The network includes multiple bridges, and each edge bridge is assigned a unique service virtual local area network (‘VLAN’) identifier. One of the bridges receives a frame for transmission to a destination node. The received frame includes a service VLAN identifier for the ingress bridge through which the frame entered the network and a customer VLAN identifier. The one bridge identifies an SPB forwarding tree in dependence upon the service VLAN identifier. The SPB forwarding tree specifies a shortest route in the network from the ingress bridge through the one bridge to the other bridges in the network. The one bridge then forwards the received frame to the egress bridge without MAC-in-MAC encapsulation in dependence upon the SPB forwarding tree and the customer VLAN identifier.