Which of the following represents a SAP on a physical port configured with Q-in-Q encapsulation?

In Nokia's Service Router Operating System (SR OS), the syntax for a Service Access Point (SAP) identifier reflects the port's encapsulation type. For Q-in-Q encapsulation (IEEE 802.1ad), which uses two VLAN tags (an outer S-TAG and an inner C-TAG), the SAP is identified using a dot notation. The format is port-id:outer-tag.inner-tag. Therefore, sap 1/1/1:10.100 correctly represents a Q-in-Q SAP on port 1/1/1 with an outer VLAN tag of 10 and an inner VLAN tag of 100.

A. sap 1/1/1 represents a port-based SAP, which typically uses null encapsulation (accepting untagged traffic).
B. sap 1/1/1:5 represents a standard Dot1q SAP, which uses a single VLAN tag (VLAN 5).
C. sap 1/1/1:5:5 is an invalid syntax for defining a Q-in-Q SAP in Nokia SR OS. The colon is used to separate the port from the first tag only.

1. Nokia 7750 SR OS Services Guide, Release 21.10.R1, "SAP Encapsulation Types and Identifiers". This section explicitly details the SAP identification formats. For QinQ, it states: "QinQ SAPs are identified by the encapsulation value and the outer and inner VLAN tags. The SAP ID is specified in the format port-id:qtag1.qtag2..."

2. Nokia 7750 SR OS Basic System Configuration Guide, Release 21.10.R1, "Ports". The section on port configuration and SAP creation details the valid syntax for different encapsulation types, confirming the port:tag.tag format for QinQ.