B.1 Introduction

3GPP44.318Generic Access Network (GAN)Mobile GAN interface layer 3 specificationRelease 17TS

The GAN-MS shall check DSCP/ToS information in incoming IP packets from the GANC and if different from what currently used, copy received DSCP/ToS and use it for outgoing IP packets.

For a tunnel mode SA, there is an "outer" IP header that specifies the IPsec processing destination, plus an "inner" IP header that specifies the ultimate destination for the packet.