With the default trust state, the SAP-ingress policy on PE-1 classifies traffic according to the 802.1p value in the customer VLAN tag. Dot1p 3 is mapped by the default dot1p-mapping table to forwarding-class h2.

Inside the MPLS core only the EXP bits that correspond to fc h2 are carried, but at PE-2 the SAP-egress policy rewrites customer QoS using the default remark-tables. According to the default IPv4 DSCP remark table, fc h2 is rewritten to DSCP af12; the default dot1p remark table rewrites fc h2 to dot1p 5. Consequently, the frame leaves PE-2 marked DSCP af12 and dot1p 5.

A. af21 corresponds to fc h1, not the fc selected for dot1p 3.

B. DSCP be is only used for fc be traffic (dot1p 0).

C. af23 is associated with fc h3, not fc h2.

F. Dot1p 2 is the remark for fc af, not fc h2.

G. Dot1p 3 is the remark for fc h1, not fc h2.

1. Nokia SR OS 22.10.R1 – Quality of Service Guide, Table 675 “Default dot1p-to-FC mapping”, p. 578.

2. Nokia SR OS 22.10.R1 – Quality of Service Guide, Table 676 “Default FC-to-dot1p remark table”, p. 579.

3. Nokia SR OS 22.10.R1 – Quality of Service Guide, Table 680 “Default FC-to-DSCP remark table (IPv4)”, p. 582.

4. Nokia SR OS 22.10.R1 – Virtual Private Routed Networks Guide, §6.3 “QoS behaviour across VPRN over MPLS”, pp. 121-125.