This read-create Integer32 (-2 to 63) sets the DSCP value used to mark the outer IP header of traffic associated with a MAP domain, with -1 meaning copy from the incoming packet and -2 meaning let the device mark it automatically; downstream packets are never re-marked. An admin tunes this to preserve QoS treatment for traffic tunneled or translated through a specific MAP domain. For example, setting it to -1 ensures a customer's already-marked voice traffic keeps its DSCP value as it passes through this domain's mapping.