Systems and techniques for processing and/or forwarding packets are described. An ingress switch can use a QoS mapping mechanism to map a first set of Quality of Service (QoS) bits in a packet received from a customer to a second set of QoS bits for use in a Transparent Interconnection of Lots of Links (TRILL) packet which encapsulates the packet. The first set of QoS bits can be different from the second set of QoS bits. The TRILL packet can be processed and/or forwarded in the network based on the second set of QoS bits. At the egress switch, the TRILL packet can be decapsulated and the original packet with the original QoS bits (or QoS bits that are different from the original QoS bits) can be forwarded to the customer's network. In this manner, some embodiments of the present invention can preserve the QoS bits across a TRILL network.