Which of the following Nokia 7750 SR components is NOT part of the data plane?

The Nokia 7750 Service Router (SR) architecture distinctly separates the control plane and the data plane. The Control Processor Module (CPM) constitutes the control plane. It runs the Service Router Operating System (SR OS) and is responsible for all management and control functions, such as running routing protocols (OSPF, BGP), managing signaling protocols (LDP, RSVP), and providing user access via CLI or SNMP. The CPM programs the forwarding information base (FIB) but does not forward user traffic itself. The data plane, responsible for high-speed packet forwarding, is composed of the Input/Output Modules (IOMs) and their associated Media Dependent Adapters (MDAs) or eXpandable Media Adapters (XMAs).

A. The Media Dependent Adapter (MDA) is a data plane component that provides the physical network interfaces and performs link-level processing before passing traffic to the IOM.
B. The Input/Output Module (IOM) is a core data plane component containing the forwarding engine (ASICs) that makes packet forwarding decisions based on the FIB provided by the CPM.
C. The eXpandable Media Adapter (XMA) is a newer, higher-density version of an MDA. It serves the same function within the data plane, providing physical interfaces for traffic.

1. Nokia 7750 Service Router Data Sheet: "The 7750 SR has a physical and functional separation of the control and data planes. The control plane functions are performed by the Control Processor Module (CPM), and the data plane functions are performed by the IOMs and MDAs." (Nokia 7750 Service Router Data Sheet, 2021, Page 4, "Architecture").

2. Nokia Service Routing Architect (SRA) Self-Study Guide: Preparing for the BGP, VPRN and Multicast Exams (Nokia Press): "The control plane is centralized on the Control Processor Module (CPM), which is the brains of the router... The data plane, also known as the forwarding plane, is a distributed architecture. Each IOM has its own forwarding engine..." (ISBN: 978-0-470-94771-9, Chapter 1, Section "7x50 Hardware Architecture", pp. 4-5).

3. Nokia SR OS R19.10.R1 System Management Guide: "The SR OS is the operating system that runs on the Control Processor Module (CPM) of the 7450 ESS, 7750 SR, and 7950 XRS. The CPM is responsible for managing the system and running the various control protocols..." (Section: "System Management Overview", Paragraph 1). This document implicitly separates the CPM's management/control role from the data forwarding hardware.