VPLS Service Configuration Commands
Page 520 7750 SR OS Services Guide
QinQ / TopQ TopQ TopQ PBits
QinQ / TopQ TopQ BottomQ BottomQ PBits
QinQ / QinQ TopQ BottomQ BottomQ PBits
Table 4: Default Dot1P Explicit Marking Actions 
Egress SAP 
Type
Ingress Packet Preserved 
Dot1P State
Marked (or Remarked) PBits
Null No preserved Dot1P bits None
Null Preserved Dot1P bits Preserved tag PBits remarked 
using dot1p-value
Dot1Q No preserved Dot1P bits New PBits marked using dot1p-
value
Dot1Q Preserved Dot1P bits Preserved tag PBits remarked 
using dot1p-value
TopQ No preserved Dot1P bits TopQ PBits marked using dot1p-
value
TopQ Preserved Dot1P bits (used as TopQ 
and BottomQ PBits)
TopQ PBits marked using dot1p-
value, BottomQ PBits preserved
QinQ No preserved Dot1P bits TopQ PBits and BottomQ PBits 
marked using dot1p-value
QinQ Preserved Dot1P bits (used as TopQ 
and BottomQ PBits)
TopQ PBits and BottomQ PBits 
marked using dot1p-value
Table 5: QinQ Mark Top Only Explicit Marking Actions
Egress SAP 
Type
Ingress Packet Preserved 
Dot1P State
Marked (or Remarked) PBits
Null No preserved Dot1P bits None
Null Preserved Dot1P bits Preserved tag PBits remarked 
using dot1p-value
Dot1Q No preserved Dot1P bits New PBits marked using dot1p-
value
Dot1Q Preserved Dot1P bits Preserved tag PBits remarked 
using dot1p-value
Table 3: Bottom Position QinQ and TopQ SAP Dot1P Evaluation  (Continued)
Port / SAP Type Existing Packet Tags PBits Used for Match