Registering a SIP extension for RC/ACO requires a user account created in the UCaaS admin portal and the SIP credentials associated with that account. These credentials are then entered in CCaaS to establish the SIP connection.

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Prerequisites

• A minimum single Essentials license is required per virtual handset in RingCentral; Basic licenses are not eligible
• A user account must be created in the RC/ACO admin interface, with a device assigned to it
• The SIP Extension, Username, Password, and Authorization ID must be obtained from the UCaaS admin portal

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Obtaining SIP Credentials from RC/ACO

1. Log into the RC/ACO admin interface
2. Navigate to Phone System > Phones & Devices > User Phones
3. Select the extension created for CCaaS
4. Select Setup & Provision > Other Phones > Select
5. The SIP Extension, Username, Password, and Authorization ID are listed at the bottom of this view. Note the Outbound Proxy listed here — confirm it matches the region used to authenticate Target Platform

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Registering the Extension in CCaaS

1. Navigate to Admin (System) > SIP Extensions
2. Select + in either Inbound Extensions or Outbound Extensions
3. Enter the following fields using the credentials obtained from the UCaaS admin portal:

4. Select Save, then OK to confirm
5. Registration typically completes within 30–60 seconds — select Refresh to update the status display

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Primary Extension (Load Balancer)

When multiple SIP extensions are registered for RC/ACO, one is designated as the primary extension — the SIP handset CCaaS uses as the load balancer to distribute calls across the other registered extensions. Use the options menu next to the extension and selectSet as Load Balancer.