In a Huawei Unified Communications (UC) solution, an intranet-only Session Controller (SC) cluster is deployed to manage session control and registration for a large number of internal users.

A. A dedicated registration SC cluster is a specific deployment role designed to offload the high volume of SIP registration requests from the core call control servers (e.g., USM), enhancing system performance and scalability. Its primary and often sole configured function is SIP registration.

B. To ensure high availability and manage load, the SC cluster supports both single-active (active/standby) for redundancy and multi-active (load sharing) distribution modes.

C. H.323 and SIP registration mechanisms are different. It is a recommended best practice to deploy a separate, standalone SC to function as an H.323 Gatekeeper, isolating H.323 RAS traffic from SIP registration traffic for stability and easier management.

D. The primary driver for deploying a dedicated registration SC cluster is scalability. When the number of SIP endpoints on the intranet becomes large, this architecture prevents the core call servers from being overwhelmed by registration traffic.

All the provided options are correct statements regarding the deployment principles and capabilities of a Huawei intranet SC cluster network.

1. Huawei SessionEngine Product Documentation (for SE1000)

"Network Planning > Typical Networking and Applications > Intranet Deployment Scenario". This section details the deployment of SC clusters within an enterprise network

outlining the rationale for dedicated registration clusters when the number of SIP users is high (supports D).

2. Huawei UC Solution V300R019 Network Planning Guide

"Chapter 4: Network Design > SC Deployment Design". This chapter specifies that for large-capacity SIP user registration

a dedicated registration SC cluster should be deployed

whose main function is to process SIP registrations (supports A).

3. Huawei SessionEngine Product Documentation (for SE1000)

"Feature Guide > High Availability > SC Cluster Modes". This document describes the supported high-availability and load-balancing mechanisms

explicitly mentioning the single-active (active/standby) and multi-active (load-sharing) modes (supports B).

4. Huawei UC Solution V300R019 Network Planning Guide

"Chapter 5: Device Deployment > Integrating H.323 Endpoints". This guide recommends deploying a standalone SC to serve as a dedicated H.323 Gatekeeper to handle H.323 endpoint registration and call control

separating it from the SIP environment (supports C).