# Connecting Unified CM to RingCentral contact center

Systems: Cisco Unified Communications Manager to RingCentral Contact Center

For A Unified CM administrator integrating enterprise telephony with a RingCentral contact center.

Canonical: https://warmtransfer.net/guides/cucm-with-ringcentral-contact-center

Last verified: 2026-09-25

Unified CM routes callers into a RingCentral contact center queue, and the contact center can deliver agent legs to Unified CM lines or transfer calls back[^48][^43]. This is inferred: pointing a RingCX External phone or SIP Route node at a Unified CM phone or DN needs an internet-reachable SIP ingress in front of Unified CM, such as CUBE, that admits RingCentral's addresses and routes the call to Unified CM[^46].

## Before you start

A CCRN is a RingEX phone number that routes calls to a contact center[^5]. A CCRN can be assigned only to Direct or Company numbers, not to numbers attached to a specific device[^6]. Numbers for RingCX voice channels are purchased or ported through RingEX and must be set up as CCRNs before use[^49]. Warm transfer from the RingCentral PBX (RingEX) to a RingCentral Contact Center CCRN is not supported[^32].

In Unified CM, call routing is built as route groups (device selection order), then route lists (route group order), then route patterns that direct matching digit strings to a gateway, trunk, or route list[^14]. A Unified CM route list can contain only route groups and local route groups, and must contain at least 1 route group[^13]. Cisco advises that a Unified CM route pattern can point directly to a gateway, but recommends configuring route lists and route groups instead[^51].

## What changes by situation

- Which RingCentral contact center product do you have? RingCX; RingCentral Contact Center.
- Where do agents take calls? RingCentral softphone; Unified CM phone.
- How should RingCentral reach Unified CM for agent legs and transfers back? PSTN; SIP via CUBE.

## Step 1: Confirm the RingCentral contact center product

**RingCX**

### Do
RingCentral announced RingCX on 2023-08-07 as a native, intelligent contact center of its own[^36]. RingCentral positioned RingCX as an additional native contact center better suited to simpler use cases, while continuing to sell RingCentral Contact Center powered by NICE[^40].

### Verify
Suggested check: Verify that the administrative portal lists the required native contact center options.

### Rollback
Suggested rollback: No configuration was applied; review account contracts if product selection must change.

**RingCentral Contact Center**

### Do
Confirm the deployment uses RingCentral Contact Center, which is RingCentral's resale of NICE CXone and is described by RingCentral as powered by NICE CXone[^34]. In July 2026 RingCentral and NICE extended their agreement to market and sell RingCentral Contact Center for an additional year[^33]. This is inferred: because the RingCentral Contact Center resale agreement was extended by only one year in July 2026, a new buyer should confirm the product's availability beyond mid-2027 before committing to it[^28]. RingCentral Contact Center agents use the NICE MAX agent application[^35].

### Verify
Suggested check: Verify administrative access to the contact center platform and confirm MAX agent application availability.

### Rollback
Suggested rollback: No configuration was applied; consult your account team if a different platform is required.

## Step 2: Configure the contact center routing number (CCRN)

**RingCX**

### Do
To make a number a RingCX CCRN, navigate in the RingEX Admin Portal to Phone System > Phone Numbers > All numbers, select the number, set Connect Calls To to Contact Center, choose Type RingCentral RingCX and the RingCX account, optionally pick a destination, and save[^8]. A CCRN can only be assigned to Direct or Company numbers[^6]. From RingEX release 26.3 (July 2026), calls to a Bring Your Own Carrier (BYOC) CCRN are routed using the PSTN so customers can run their own PBX IVR before the call reaches RingCentral[^3].

### Verify
Suggested check: Confirm that the selected phone number shows Connect Calls To set to Contact Center.

### Rollback
During a RingCX outage, an admin can temporarily reroute a CCRN by changing it to connect to an extension whose forwarding rules send calls elsewhere[^7].

**RingCentral Contact Center**

### Do
Setting up a RingCentral Contact Center CCRN is done by submitting a case or contacting RingCentral support, together with setting up the contact center Point of Contact[^30]. In RingCentral Contact Center, a CCRN routes a local, toll-free, or IVN number to the contact center platform, and any call to the CCRN goes immediately to the contact center Point of Contact (POC)[^29].

### Verify
Suggested check: Confirm that the CCRN and its associated Point of Contact are active in your tenant.

### Rollback
Suggested rollback: Submit a support case to reassign or release the Point of Contact and routing number mapping.

## Step 3: Build the contact center destination

**RingCX**

### Do
RingCentral orders RingCX inbound voice setup as audio library, IVR workflow, inbound voice queues, queue metrics, linking workflows to queues, voice channel destinations, agent queue assignment, and agent experience[^22]. A RingCX voice channel is created in the RingCX Admin Portal under Channels > New channel > Voice, and it receives calls only while its Active box is checked[^50]. A RingCX voice channel lets customers reach the business by calling a RingCX phone number and routes those calls to a destination such as an inbound queue, a workflow, or a cloud destination[^48]. In RingCX queue settings, DNIS is the destination number, usually the inbound number callers dial to reach the contact center[^27].

### Verify
Suggested check: Verify that the Active checkbox on the voice channel is selected and that the assigned queue or workflow is ready to accept interactions.

### Rollback
Suggested rollback: Uncheck the Active checkbox on the voice channel in the administrative portal to stop receiving calls.

**RingCentral Contact Center**

### Do
In RingCentral Contact Center a CCRN routes a local, toll-free or IVN number to the contact center platform, and any call to the CCRN goes immediately to the contact center Point of Contact (POC)[^29]. Setting up a RingCentral Contact Center CCRN is done by submitting a case or contacting RingCentral support, together with setting up the contact center Point of Contact[^30].

### Verify
Suggested check: Verify that the Point of Contact is mapped to an active queue or script in the contact center platform.

### Rollback
Suggested rollback: Contact support to re-point the Point of Contact to an alternative script or holding treatment.

## Step 4: Route Unified CM callers to the CCRN

### Do
For RingCX, this is inferred: RingCentral's RingCX number documentation describes numbers bought or ported through RingEX and made CCRNs, and no RingCentral page found describes a SIP trunk from a third-party PBX such as Unified CM into RingCX, so Unified CM reaches RingCX by dialing a CCRN over the PSTN[^26]. Unified CM call routing is built as route groups (device selection order), then route lists (route group order), then route patterns that direct matching digit strings to a gateway, trunk, or route list[^14]. A Unified CM route list can contain only route groups and local route groups, and must contain at least 1 route group[^13]. Cisco advises that a Unified CM route pattern can point directly to a gateway, but recommends configuring route lists and route groups instead[^51].

### Verify
Suggested check: Place a call from a desk extension to the CCRN digit pattern and verify that the call egresses the designated gateway or trunk.

### Rollback
Suggested rollback: Remove the newly added route pattern.

## Step 5: Configure the return edge on CUBE

**PSTN + RingCX**

### Do
For RingCX, agent legs arrive from a PSTN destination[^44].

### Verify
Suggested check: Place a test PSTN call from an external line to the enterprise DID range to confirm carrier delivery to Unified CM.

### Rollback
Suggested rollback: No configuration changes were made.

**SIP via CUBE + RingCX**

### Do
Cisco Unified Border Element bridges 2 separate VoIP networks, connects enterprise networks to ITSPs, and provides address and port translation for privacy and topology hiding[^10]. This is inferred: pointing a RingCX External phone or SIP Route node at a Unified CM phone or DN needs an internet-reachable SIP ingress in front of Unified CM, such as CUBE, that admits RingCentral's addresses and routes the call to Unified CM[^46].

By default, CUBE trusts inbound SIP from addresses in dial-peer session targets and voice class server groups and silently discards inbound calls that fail the IP trusted-list check[^11]. RingCX network requirements publish a list of RingCentral IP supernets, including 66.81.240.0/20 and 208.87.40.0/22, advertised via BGP for its communication services[^39].

Cisco recommends configuring CUBE to route calls only for known phone number ranges or SIP URIs[^9]. CUBE can select an inbound dial peer by matching parts of the URI sent by the neighbouring SIP entity, for example matching the top Via host IP with a voice class uri and 'incoming uri via'[^12]. A voice class uri can match on host (hostname pattern, IPv4, IPv6, or DNS), user-id, or pattern (the entire URI string)[^52]. voice class uri patterns are case-sensitive and the pattern, user-id, and hostname are limited to 32 characters[^53]. A voice class uri can contain at most 10 host ipv4/ipv6/dns entries in total and only 1 host hostname-pattern entry[^54]. Inbound dial-peer matching by URI works only for SIP (voip session protocol sipv2) and a dial peer can carry only 1 incoming uri match[^55]. incoming uri via matches against the topmost Via header, which identifies the last hop, and Cisco recommends it when the call traverses multiple SIP hops[^56].

Unified CM uses SIP trunks to connect to external devices such as SIP gateways, SIP proxy servers, UC applications, remote clusters, or Session Management Edition[^17]. The Unified CM SIP trunk task flow runs: configure a SIP profile, configure a SIP trunk security profile, then configure the SIP trunk applying both[^16]. A Unified CM SIP trunk can have up to 16 destination addresses given as IPv4 or IPv6 addresses, FQDNs, or a single DNS SRV record[^15]. Checking Run on All Active Unified CM Nodes enables a SIP trunk on all cluster nodes[^57].

### Verify
Cisco's basic debug set for SIP calls on CUBE is `debug ccsip messages` and `debug ccsip error`, with `debug ccsip non-call` optional, and `debug voip ccapi inout` recommended alongside because it usually has minimal CPU impact[^58]. Before debugging, Cisco recommends logging to a 10 MB buffer (`logging buffered 10000000`), disabling console and monitor logging, and millisecond timestamps; debugs should be stopped (`undebug all`) if CPU exceeds 80%[^59]. `show call active voice brief` shows, per call leg, `pid:<peer_id>` (the dial-peer tag used for that leg) and the direction Answer or Originate, which is how the matched inbound and outbound dial peers are confirmed for a live call[^60]. Useful verification commands for this configuration include `show dial-peer voice summary` (operational status and keepalive), `show voice class uri`, `show voice class dpg`, `show voice class server-group`, and `show dialplan incall sip`[^61].

### Rollback
Suggested rollback: Remove the inbound dial peers and trust list entries on the border router, and delete or disable the SIP trunk in call manager administration.

**PSTN + RingCentral Contact Center**

### Do
For RingCentral Contact Center, voice contacts are delivered to the phone number configured by the agent in MAX[^25].

### Verify
Suggested check: Place a test PSTN call from an external line to the enterprise DID range to confirm carrier delivery to Unified CM.

### Rollback
Suggested rollback: No configuration changes were made.

**SIP via CUBE + RingCentral Contact Center**

### Do
NICE lists routing calls directly from a customer PBX among CXone number-connectivity options, alongside porting, RespOrg for toll-free, remote call forwarding, and an independent carrier[^19]. This is inferred: because RingCentral Contact Center is powered by CXone and uses MAX, NICE's CXone MAX documentation is the best available description of its agent phone options, but a RingCentral tenant may not expose every CXone option[^31].

### Verify
Suggested check: Check tenant documentation or contact support to confirm whether customer PBX SIP trunking is enabled for your tenant.

### Rollback
Suggested rollback: Do not proceed with SIP CUBE provisioning; configure agent connectivity and routing via PSTN DIDs instead.

## Step 6: Connect agent voice paths

**RingCentral softphone + PSTN + RingCX**

### Do
RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone[^43]. RingCX network requirements list UDP 20000-64999 for RTP/SRTP media, TCP 8083 for SIP/WSS/DTLS signaling, and TCP 8080 WSS for agent connectivity[^38]. RingCX voice needs at least 128 Kbps of dedicated bandwidth per agent in each direction, with DSCP-based QoS recommended[^37].

### Verify
Suggested check: Have an agent log in using the integrated softphone, make an outbound interaction, and confirm bi-directional voice.

### Rollback
Suggested rollback: Instruct agents to select an external phone endpoint at login.

**RingCentral softphone + SIP via CUBE + RingCX**

### Do
RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone[^43]. RingCX network requirements list UDP 20000-64999 for RTP/SRTP media, TCP 8083 for SIP/WSS/DTLS signaling, and TCP 8080 WSS for agent connectivity[^38]. RingCX voice needs at least 128 Kbps of dedicated bandwidth per agent in each direction, with DSCP-based QoS recommended[^37].

### Verify
Suggested check: Have an agent log in using the integrated softphone, make an outbound interaction, and confirm bi-directional voice.

### Rollback
Suggested rollback: Instruct agents to select an external phone endpoint at login.

**Unified CM phone + PSTN + RingCX**

### Do
RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone[^43]. The RingCX Workflow Studio Route node can send a call to a Voice Queue, Cloud Profile, Track, PSTN number, SIP destination, or Digital Queue[^44].

### Verify
Suggested check: Trigger a queue interaction to an agent logged in with an external phone and verify that the desk phone rings.

### Rollback
Suggested rollback: Change the agent login selection to the integrated softphone.

**Unified CM phone + SIP via CUBE + RingCX**

### Do
RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone[^43]. This is inferred: pointing a RingCX External phone or SIP Route node at a Unified CM phone or DN needs an internet-reachable SIP ingress in front of Unified CM, such as CUBE, that admits RingCentral's addresses and routes the call to Unified CM[^46]. Cisco recommends configuring CUBE to route calls only for known phone number ranges or SIP URIs[^9].

### Verify
Suggested check: Verify that inbound calls to the agent SIP URI match the configured CUBE dial peer and ring the Unified CM phone.

### Rollback
Suggested rollback: Revert agent login configuration to the integrated softphone or PSTN DID.

**RingCentral softphone + PSTN + RingCentral Contact Center**

### Do
RingCentral Contact Center agents use the NICE MAX agent application, and RingCentral enables its integrated softphone by turning on 'Agent Softphone (Requires MAX)' in an Admin > Security Profile's Agent permissions once MAX is enabled on the Business Unit[^35]. When launching NICE CXone MAX, the agent chooses Set Phone Number, Set Station ID, or Integrated Softphone[^25]. CXone Integrated Softphone uses the WebRTC feature in the agent's Chrome browser to transmit voice[^62]. CXone Integrated Softphone (WebRTC) needs outbound HTTPS port 443 and UDP ports 1024-65535 through the corporate and workstation firewalls[^63].

### Verify
Suggested check: Launch MAX with Integrated Softphone selected and confirm the softphone connects successfully.

### Rollback
Suggested rollback: Deselect 'Agent Softphone (Requires MAX)' in the agent's security profile.

**RingCentral softphone + SIP via CUBE + RingCentral Contact Center**

### Do
RingCentral Contact Center agents use the NICE MAX agent application, and RingCentral enables its integrated softphone by turning on 'Agent Softphone (Requires MAX)' in an Admin > Security Profile's Agent permissions once MAX is enabled on the Business Unit[^35]. When launching NICE CXone MAX, the agent chooses Set Phone Number, Set Station ID, or Integrated Softphone[^25]. CXone Integrated Softphone uses the WebRTC feature in the agent's Chrome browser to transmit voice[^62]. CXone Integrated Softphone (WebRTC) needs outbound HTTPS port 443 and UDP ports 1024-65535 through the corporate and workstation firewalls[^63].

### Verify
Suggested check: Launch MAX with Integrated Softphone selected and confirm the softphone connects successfully.

### Rollback
Suggested rollback: Deselect 'Agent Softphone (Requires MAX)' in the agent's security profile.

**Unified CM phone + PSTN + RingCentral Contact Center**

### Do
When launching NICE CXone MAX, the agent chooses Set Phone Number, Set Station ID, or Integrated Softphone, and a phone number is where the platform delivers the agent's voice contacts[^25]. This is inferred: when an agent uses Set Phone Number or a station with a Unified CM number, CXone places the agent leg as a call to that number, so the number must be reachable from the network CXone uses for the B leg (PSTN DID or a SIP path to Unified CM)[^64].

### Verify
Suggested check: Confirm that MAX dials the configured PSTN DID when an interaction is delivered.

### Rollback
Suggested rollback: Re-launch MAX and select Integrated Softphone.

**Unified CM phone + SIP via CUBE + RingCentral Contact Center**

### Do
This is inferred: because RingCentral Contact Center is powered by CXone and uses MAX, NICE's CXone MAX documentation is the best available description of its agent phone options, but a RingCentral tenant may not expose every CXone option[^31]. When launching NICE CXone MAX, the agent chooses Set Phone Number, Set Station ID, or Integrated Softphone, and a phone number is where the platform delivers the agent's voice contacts[^25]. This is inferred: when an agent uses Set Phone Number or a station with a Unified CM number, CXone places the agent leg as a call to that number, so the number must be reachable from the network CXone uses for the B leg (PSTN DID or a SIP path to Unified CM)[^64].

### Verify
Suggested check: Confirm that MAX dials the configured PSTN DID when an interaction is delivered.

### Rollback
Suggested rollback: Re-launch MAX and select Integrated Softphone.

## Step 7: Manage the persistent agent leg

**RingCX**

### Do
RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone[^43].

### Verify
Suggested check: Verify that after completing a call, the voice path remains open and subsequent queue calls connect without redialing the endpoint.

### Rollback
Suggested rollback: Disconnect the call or log out and log back in without selecting persistent voice connection.

**RingCentral Contact Center**

### Do
In CXone, the portion of a call between CXone and the agent is called the B leg or agent leg, and it is the agent's audio connection to CXone for calls and voicemails[^65]. In CXone MAX, an agent connects the voice path with the Connect button in the Agent Leg area, and keeping that connection active avoids reconnecting the voice path for each new call[^2]. A CXone MAX voice connection may disconnect automatically after an administrator-configured idle time[^1].

### Verify
Suggested check: In MAX, observe the Agent Leg status indicator showing connected, and verify that subsequent calls do not ring the physical phone again.

### Rollback
Suggested rollback: Hang up the agent leg or disconnect the session in MAX.

## Step 8: Configure agent call transfers back to Unified CM

**RingCX**

### Do
RingCX agent security permissions include Transfer permissions that govern using the Transfer button, transferring internationally, and the scope of direct transfers to agents[^41]. RingCX agents can cold transfer (without speaking to the recipient), warm transfer (speak first, optionally conferencing more parties), or transfer to voicemail, and can requeue a call to a different queue[^42]. A RingCX inbound queue has a Transfer Override Caller ID setting that sets the 10-digit number shown to recipients of calls transferred from that queue[^47].

This is inferred: an agent on a Unified CM phone who transfers with the phone's own Transfer key rather than the contact center agent application risks the contact center losing track of the call, so agents should transfer from the agent application[^20].

### Verify
Suggested check: Perform both a cold and warm transfer from the agent interface to a Unified CM extension and verify audio connectivity.

### Rollback
Suggested rollback: Revoke transfer permissions from the agent security profile in the portal.

**RingCentral Contact Center**

### Do
In MAX, an agent transfers a call by clicking Transfer / Conf, typing a number or picking an address-book entry, clicking Call, then clicking Transfer, which can be done before the new party answers[^23]. In MAX, once the second party answers, the agent can click Conference so all 3 can speak, then Transfer for the conference leg to leave, or Hang Up for that leg to keep the original contact[^24]. In NICE CXone, a call transfer introduces a second B leg (agent leg)[^66]. NICE cautions that using a hard phone's own features, such as transferring on the device instead of in MAX, can make CXone reporting inaccurate[^21].

### Verify
Suggested check: Execute a transfer to a Unified CM number in MAX and verify that the contact state clears in MAX after completion.

### Rollback
Suggested rollback: No configuration change is required; train agents to transfer calls exclusively using MAX controls.

## Step 9: Configure automated IVR routing to Unified CM

**PSTN + RingCX**

### Do
The RingCX Workflow Studio Route node can send a call to a Voice Queue, Cloud Profile, Track, PSTN number, SIP destination, or Digital Queue[^44]. For PSTN and SIP Route node destinations, RingCX lets the admin set Caller ID (ANI, DNIS, or a custom 10-digit number), Ring Duration, recording start/stop, music on hold, TT Accept, whisper, and post-dial audio[^45].

### Verify
Suggested check: Place a test call to the IVR workflow, select the transfer option, and verify that the call reaches the Unified CM destination over the PSTN.

### Rollback
Suggested rollback: In Workflow Studio, remove the Route node or redirect the workflow branch back to a voice queue.

**SIP via CUBE + RingCX**

### Do
The RingCX Workflow Studio Route node can send a call to a Voice Queue, Cloud Profile, Track, PSTN number, SIP destination, or Digital Queue[^44]. For PSTN and SIP Route node destinations, RingCX lets the admin set Caller ID (ANI, DNIS, or a custom 10-digit number), Ring Duration, recording start/stop, music on hold, TT Accept, whisper, and post-dial audio[^45]. This is inferred: pointing a RingCX External phone or SIP Route node at a Unified CM phone or DN needs an internet-reachable SIP ingress in front of Unified CM, such as CUBE, that admits RingCentral's addresses and routes the call to Unified CM[^46]. Cisco recommends configuring CUBE to route calls only for known phone number ranges or SIP URIs[^9].

### Verify
Suggested check: Place a test call to the IVR workflow and verify that the SIP destination invokes CUBE and delivers the call to Unified CM.

### Rollback
Suggested rollback: Re-point the Route node destination to an internal voice queue in Workflow Studio.

**PSTN + RingCentral Contact Center**

### Do
In RingCentral Contact Center, a CCRN routes a local, toll-free, or IVN number to the contact center platform, and any call to the CCRN goes immediately to the contact center Point of Contact (POC)[^29]. Setting up a RingCentral Contact Center CCRN is done by submitting a case or contacting RingCentral support, together with setting up the contact center Point of Contact[^30].

### Verify
Suggested check: Call the Point of Contact number and verify the scripted transfer to the target Unified CM DID.

### Rollback
Suggested rollback: Revert the script to previous routing logic.

**SIP via CUBE + RingCentral Contact Center**

### Do
This is inferred: because RingCentral Contact Center is powered by CXone and uses MAX, NICE's CXone MAX documentation is the best available description of its agent phone options, but a RingCentral tenant may not expose every CXone option[^31]. When launching NICE CXone MAX, the agent chooses Set Phone Number, Set Station ID, or Integrated Softphone, and a phone number is where the platform delivers the agent's voice contacts[^25].

### Verify
Suggested check: Call the Point of Contact number and verify the scripted transfer over the PSTN to Unified CM.

### Rollback
Suggested rollback: Revert the script to previous routing logic.

## Step 10: Rehearse outage rerouting

**RingCX**

### Do
During a RingCX outage, an admin can temporarily reroute a CCRN by changing it to connect to an extension whose forwarding rules send calls elsewhere[^7].

### Verify
Suggested check: Temporarily switch the CCRN destination to the designated extension and confirm calls route immediately to the backup Unified CM destination.

### Rollback
In the RingEX Admin Portal under Phone System > Phone Numbers > All numbers, select the CCRN, set Connect Calls To back to Contact Center, and select Type RingCentral RingCX[^8].

**RingCentral Contact Center**

### Do
Setting up a RingCentral Contact Center CCRN is done by submitting a case or contacting RingCentral support, together with setting up the contact center Point of Contact[^30].

### Verify
Suggested check: Review documented contact numbers and ticketing escalation procedures with your account team.

### Rollback
Suggested rollback: Follow documented vendor procedures to revert emergency routing changes.

## Applicability

Applies to: NICE CXone Mpower MAX, RingCentral RingEX, Cisco Unified Border Element, Cisco Unified Communications Manager, NICE CXone Mpower, RingCentral RingCX, RingCentral Contact Center, Cisco IOS XE voice gateways, and NICE CXone Integrated Softphone. Deployments: on-premises and multi-tenant. Sources checked 2026-09-25. RingEX release 26.3 and later covers routing to BYOC CCRN numbers over the PSTN[^3]. RingCentral Contact Center Point of Contact and CCRN support applies to the United States region[^29][^30]. Transfer Override Caller ID in RingCX is documented for the North American Numbering Plan (NANP) region[^47].

## What remains uncertain

A direct SIP trunk from Unified CM into RingCX or RingCentral Contact Center is not covered by the sources below. Specific SIP transport, TLS certificates, SRTP parameters, audio codecs, and source IP addresses for RingCentral SIP legs directed to CUBE are not covered by the sources below. CXone Studio script building and scripted transfer mechanics for RingCentral Contact Center are not covered by the sources below. Emergency calling handling and location reporting for agents taking contact center calls on Unified CM phones are not covered by the sources below. Call recording behavior on external-phone legs and desktop CTI integrations between Unified CM and RingCentral are not covered by the sources below.

## Sources

[^1]: A CXone MAX voice connection may disconnect automatically after an administrator-configured idle time. Source: [Connect Your Phone in MAX](https://help.nicecxone.com/content/agent/max/voice/connectyourphone.htm), note on automatic disconnection. Checked 2026-09-25.
[^2]: In CXone MAX an agent connects the voice path with the Connect button in the Agent Leg area, and keeping that connection active avoids reconnecting the voice path for each new call. Source: [Connect Your Phone in MAX](https://help.nicecxone.com/content/agent/max/voice/connectyourphone.htm), Connect your phone procedure. Checked 2026-09-25.
[^3]: From RingEX release 26.3 (July 2026), calls to a Bring Your Own Carrier (BYOC) CCRN are routed using the PSTN so customers can run their own PBX IVR before the call reaches RingCentral. Source: [RingEX Core Release Notes](https://support.ringcentral.com/release-notes/ringex/ringex-core.html), Version 26.3, Global, 'Routing to BYOC CCRN numbers'. Checked 2026-09-25.
[^4]: Assigning a RingCX CCRN in the RingEX Admin Portal requires an administrator with phone system admin privileges. Source: [Setting up a RingEX CCRN for RingCX](https://support.ringcentral.com/article-v2/Setting-up-a-CCRN-in-RingEX.html?brand=RingCentral&product=RingCX&language=en_US), Assigning a CCRN in RingEX, prerequisites. Checked 2026-09-25.
[^5]: A Contact Center Routing Number (CCRN) is a RingEX phone number that routes calls to a contact center. Source: [Setting up a RingEX CCRN for RingCX](https://support.ringcentral.com/article-v2/Setting-up-a-CCRN-in-RingEX.html?brand=RingCentral&product=RingCX&language=en_US), introduction. Checked 2026-09-25.
[^6]: A CCRN can be assigned only to Direct or Company numbers, not to numbers attached to a specific device. Source: [Setting up a RingEX CCRN for RingCX](https://support.ringcentral.com/article-v2/Setting-up-a-CCRN-in-RingEX.html?brand=RingCentral&product=RingCX&language=en_US), Assigning a CCRN in RingEX. Checked 2026-09-25.
[^7]: During a RingCX outage an admin can temporarily reroute a CCRN by changing it to connect to an extension whose forwarding rules send calls elsewhere. Source: [Setting up a RingEX CCRN for RingCX](https://support.ringcentral.com/article-v2/Setting-up-a-CCRN-in-RingEX.html?brand=RingCentral&product=RingCX&language=en_US), Switching a CCRN in RingEX to route calls externally. Checked 2026-09-25.
[^8]: To make a number a RingCX CCRN, in the RingEX Admin Portal go to Phone System > Phone Numbers > All numbers, select the number, set Connect Calls To to Contact Center, choose Type RingCentral RingCX and the RingCX account, optionally pick a destination, and save. Source: [Setting up a RingEX CCRN for RingCX](https://support.ringcentral.com/article-v2/Setting-up-a-CCRN-in-RingEX.html?brand=RingCentral&product=RingCX&language=en_US), Assigning a CCRN in RingEX. Checked 2026-09-25.
[^9]: Cisco recommends configuring CUBE to route calls only for known phone number ranges or SIP URIs. Source: [Cisco Guide to Harden Cisco Unified Border Element (CUBE) Enterprise Devices](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/220380-cisco-guide-to-harden-cisco-unified-bord.html), Call Routing and Toll Fraud. Checked 2026-09-25.
[^10]: Cisco Unified Border Element bridges two separate VoIP networks, connects enterprise networks to ITSPs, and provides address and port translation for privacy and topology hiding. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Overview of Cisco Unified Border Element](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/voi-cube-overview.html), Overview of Cisco Unified Border Element. Checked 2026-09-25.
[^11]: By default CUBE trusts inbound SIP from addresses in dial-peer session targets and voice class server groups and silently discards inbound calls that fail the IP trusted-list check. Source: [Cisco Guide to Harden Cisco Unified Border Element (CUBE) Enterprise Devices](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/220380-cisco-guide-to-harden-cisco-unified-bord.html), IP Address Trusted List section. Checked 2026-09-25.
[^12]: CUBE can select an inbound dial peer by matching parts of the URI sent by the neighbouring SIP entity, for example matching the top Via host IP with a voice class uri and 'incoming uri via'. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), feature overview; IPv4 host configuration example. Checked 2026-09-25.
[^13]: A Unified CM route list can contain only route groups and local route groups, and must contain at least one route group. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Call Routing](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_010010.html), Route List overview. Checked 2026-09-25.
[^14]: Unified CM call routing is built as route groups (device selection order), then route lists (route group order), then route patterns that direct matching digit strings to a gateway, trunk or route list. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Call Routing](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_010010.html), Call Routing Configuration Task Flow; Route Pattern overview. Checked 2026-09-25.
[^15]: A Unified CM SIP trunk can have up to 16 destination addresses given as IPv4 or IPv6 addresses, FQDNs, or a single DNS SRV record. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Trunks](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_01000.html), Configure SIP Trunks. Checked 2026-09-25.
[^16]: Unified CM SIP trunk setup runs: configure a SIP profile, configure a SIP trunk security profile, then configure the SIP trunk applying both. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Trunks](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_01000.html), SIP Trunk Configuration Task Flow. Checked 2026-09-25.
[^17]: Unified CM uses SIP trunks to connect to external devices such as SIP gateways, SIP proxy servers, UC applications, remote clusters or Session Management Edition. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Trunks](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_01000.html), SIP Trunk Overview. Checked 2026-09-25.
[^18]: In CXone the A leg is the call portion between the contact and CXone and the B leg, or agent leg, is the portion between CXone and the agent, both joined through a CXone media server. Source: [Connectivity in NiCE CXone](https://help.incontact.com/Content/GlobalFeatures/Connectivity/ConnectivityInCXone.htm), A leg and B leg definitions. Checked 2026-09-25.
[^19]: NICE lists routing calls directly from a customer PBX among CXone number-connectivity options, alongside porting, RespOrg for toll-free, remote call forwarding and an independent carrier. Source: [Connectivity in NiCE CXone](https://help.incontact.com/Content/GlobalFeatures/Connectivity/ConnectivityInCXone.htm), phone number management options. Checked 2026-09-25.
[^20]: An agent on a Unified CM phone who transfers with the phone's own Transfer key rather than the contact center agent application risks the contact center losing track of the call, so agents should transfer from the agent application (inferred). Source: [Connect Your Phone in MAX](https://help.nicecxone.com/content/agent/max/voice/connectyourphone.htm), caution on hard phone features. Checked 2026-09-25.
[^21]: NICE cautions that using a hard phone's own features, such as transferring on the device instead of in MAX, can make CXone reporting inaccurate. Source: [Connect Your Phone in MAX](https://help.nicecxone.com/content/agent/max/voice/connectyourphone.htm), caution on hard phone features. Checked 2026-09-25.
[^22]: RingCentral orders RingCX inbound voice setup as audio library, IVR workflow, inbound voice queues, queue metrics, linking workflows to queues, voice channel destinations, agent queue assignment and agent experience. Source: [Setting up your inbound voice contact center in RingCX](https://support.ringcentral.com/article-v2/setting-up-your-inbound-voice-contact-center-in-ringcx.html?brand=RingCentral&product=RingCX&language=en_US), numbered section headings. Checked 2026-09-25.
[^23]: In MAX an agent transfers a call by clicking Transfer / Conf, typing a number or picking an address-book entry, clicking Call, then clicking Transfer, which can be done before the new party answers. Source: [Handle Calls in MAX](https://help.nicecxone.com/Content/agent/max/voice/handlecalls.htm), Transfer a call. Checked 2026-09-25.
[^24]: In MAX, once the second party answers, the agent can click Conference so all three can speak, then Transfer for the conference leg to leave, or Hang Up for that leg to keep the original contact. Source: [Handle Calls in MAX](https://help.nicecxone.com/Content/agent/max/voice/handlecalls.htm), Conference / warm transfer. Checked 2026-09-25.
[^25]: When launching NICE CXone MAX the agent chooses Set Phone Number, Set Station ID or Integrated Softphone, and a phone number is where the platform delivers the agent's voice contacts. Source: [Launch MAX Agent](https://help.nicecxone.com/content/agent/max/launchmaxagent.htm), Launch MAX Agent procedure. Checked 2026-09-25.
[^26]: RingCentral's RingCX number documentation describes numbers bought or ported through RingEX and made CCRNs, and no RingCentral page found describes a SIP trunk from a third-party PBX such as Unified CM into RingCX, so Unified CM reaches RingCX by dialing a CCRN over the PSTN (inferred). Source: [Configuring a voice channel in RingCX](https://support.ringcentral.com/article-v2/configuring-a-voice-channel.html?brand=RingCentral&product=RingCX&language=en_US), prerequisites before configuration steps. Checked 2026-09-25.
[^27]: In RingCX queue settings DNIS is the destination number, usually the inbound number callers dial to reach the contact center. Source: [Configuring inbound queue settings in RingCX](https://support.ringcentral.com/article-v2/Configuring-inbound-queue-settings-in-RingCX.html?brand=RingCentral&product=RingCX&language=en_US), General tab, DNIS. Checked 2026-09-25.
[^28]: Because the RingCentral Contact Center resale agreement was extended by only one year in July 2026, a new buyer should confirm the product's availability beyond mid-2027 before committing to it (inferred). Source: [NiCE and RingCentral Expand Strategic Partnership to Orchestrate the Future of AI-Powered Customer and Employee Experiences](https://www.ringcentral.com/whyringcentral/company/pressreleases/nice-and-ringcentral-expand-strategic-partnership-to-orchestrate-the-future-of-ai-powered-customer-and-employee-experiences.html), paragraph on extending the existing agreement. Checked 2026-09-25.
[^29]: In RingCentral Contact Center a CCRN routes a local, toll-free or IVN number to the contact center platform, and any call to the CCRN goes immediately to the contact center Point of Contact (POC). Source: [Contact Center Routing Number (CCRN)](https://support.ringcentral.com/article-v2/Contact-Center-Routing-Number-CCRN-RingCentral-Contact-Center.html?brand=RC_US&product=RingCentral_Contact_Center&language=en_US), Contact Center Routing Number (CCRN) Overview; CCRN Routes Call to Same POC. Checked 2026-09-25.
[^30]: Setting up a RingCentral Contact Center CCRN is done by submitting a case or contacting RingCentral support, together with setting up the contact center Point of Contact. Source: [Contact Center Routing Number (CCRN)](https://support.ringcentral.com/article-v2/Contact-Center-Routing-Number-CCRN-RingCentral-Contact-Center.html?brand=RC_US&product=RingCentral_Contact_Center&language=en_US), Contact Center Routing Number (CCRN) Overview. Checked 2026-09-25.
[^31]: Because RingCentral Contact Center is powered by CXone and uses MAX, NICE's CXone MAX documentation is the best available description of its agent phone options, but a RingCentral tenant may not expose every CXone option (inferred). Source: [Activate MAX Integrated Softphone - RingCentral Contact Center](https://support.ringcentral.com/article-v2/Activate-MAX-Integrated-Softphone-RingCentral-Contact-Center.html?brand=RC_US&product=RingCentral_Contact_Center&language=en_US), activation steps (MAX references). Checked 2026-09-25.
[^32]: RingCentral states that warm transfer from the RingCentral PBX to a RingCentral Contact Center CCRN is not supported. Source: [Contact Center Routing Number (CCRN)](https://support.ringcentral.com/article-v2/Contact-Center-Routing-Number-CCRN-RingCentral-Contact-Center.html?brand=RC_US&product=RingCentral_Contact_Center&language=en_US), Contact Center Routing Number (CCRN) Overview, limitation note. Checked 2026-09-25.
[^33]: In July 2026 RingCentral and NICE extended their agreement to market and sell RingCentral Contact Center for an additional year. Source: [NiCE and RingCentral Expand Strategic Partnership to Orchestrate the Future of AI-Powered Customer and Employee Experiences](https://www.ringcentral.com/whyringcentral/company/pressreleases/nice-and-ringcentral-expand-strategic-partnership-to-orchestrate-the-future-of-ai-powered-customer-and-employee-experiences.html), paragraph on extending the existing agreement. Checked 2026-09-25.
[^34]: RingCentral Contact Center is RingCentral's resale of NICE CXone, described by RingCentral as powered by NiCE CXone. Source: [NiCE and RingCentral Expand Strategic Partnership to Orchestrate the Future of AI-Powered Customer and Employee Experiences](https://www.ringcentral.com/whyringcentral/company/pressreleases/nice-and-ringcentral-expand-strategic-partnership-to-orchestrate-the-future-of-ai-powered-customer-and-employee-experiences.html), paragraph on extending the existing agreement. Checked 2026-09-25.
[^35]: RingCentral Contact Center agents use the NICE MAX agent application, and RingCentral enables its integrated softphone by turning on 'Agent Softphone (Requires MAX)' in an Admin > Security Profile's Agent permissions once MAX is enabled on the Business Unit. Source: [Activate MAX Integrated Softphone - RingCentral Contact Center](https://support.ringcentral.com/article-v2/Activate-MAX-Integrated-Softphone-RingCentral-Contact-Center.html?brand=RC_US&product=RingCentral_Contact_Center&language=en_US), activation steps. Checked 2026-09-25.
[^36]: RingCentral announced RingCX on 2023-08-07 as a native, intelligent contact center of its own. Source: [RingCentral Unveils RingCX – A Native, Intelligent Contact Center Solution](https://www.ringcentral.com/whyringcentral/company/pressreleases/ringcentral-unveils-ringcx-a-native-intelligent-contact-center-solution.html), dateline and first paragraph. Checked 2026-09-25.
[^37]: RingCX voice needs at least 128 Kbps of dedicated bandwidth per agent in each direction, with DSCP-based QoS recommended. Source: [RingCX network requirements](https://support.ringcentral.com/article-v2/RingCX-network-requirements.html?brand=RingCentral&product=RingCX&language=en_US), Endpoint and network guidelines; Quality of Service (QoS) guidelines. Checked 2026-09-25.
[^38]: RingCX network requirements list UDP 20000-64999 for RTP/SRTP media, TCP 8083 for SIP/WSS/DTLS signaling and TCP 8080 WSS for agent connectivity. Source: [RingCX network requirements](https://support.ringcentral.com/article-v2/RingCX-network-requirements.html?brand=RingCentral&product=RingCX&language=en_US), RingCX region port table. Checked 2026-09-25.
[^39]: RingCX network requirements publish a list of RingCentral IP supernets, including 66.81.240.0/20 and 208.87.40.0/22, advertised via BGP for its communication services. Source: [RingCX network requirements](https://support.ringcentral.com/article-v2/RingCX-network-requirements.html?brand=RingCentral&product=RingCX&language=en_US), IP supernets. Checked 2026-09-25.
[^40]: RingCentral positioned RingCX as an additional native contact center better suited to simpler use cases, while continuing to sell RingCentral Contact Center powered by NICE. Source: [RingCentral Unveils RingCX – A Native, Intelligent Contact Center Solution](https://www.ringcentral.com/whyringcentral/company/pressreleases/ringcentral-unveils-ringcx-a-native-intelligent-contact-center-solution.html), quote attributed to CEO Vlad Shmunis. Checked 2026-09-25.
[^41]: RingCX agent security permissions include Transfer permissions that govern using the Transfer button, transferring internationally, and the scope of direct transfers to agents. Source: [Managing agent security permissions in RingCX](https://support.ringcentral.com/article-v2/Configuring-agent-permissions-in-RingCX.html?brand=RingCentral&product=RingCX&language=en_US), Transfer permissions. Checked 2026-09-25.
[^42]: RingCX agents can cold transfer (without speaking to the recipient), warm transfer (speak first, optionally conferencing more parties) or transfer to voicemail, and can requeue a call to a different queue. Source: [Transferring a call in RingCX](https://support.ringcentral.com/article-v2/Transferring-a-call-in-RingCX.html?brand=RingCentral&product=RingCX&language=en_US), transfer type list; requeue pointer. Checked 2026-09-25.
[^43]: RingCX agents can make and receive calls using the integrated softphone, an external phone, or a RingCentral phone. Source: [Intro to the RingCX agent interface](https://support.ringcentral.com/article-v2/Intro-to-the-RingCX-agent-interface.html?brand=RingCentral&product=RingCX&language=en_US), Making and receiving calls. Checked 2026-09-25.
[^44]: The RingCX Workflow Studio Route node can send a call to a Voice Queue, Cloud Profile, Track, PSTN number, SIP destination or Digital Queue. Source: [Using the Route node in the RingCX Workflow Studio](https://support.ringcentral.com/article-v2/Using-the-Route-node-in-the-RingCX-IVR-Studio.html?brand=RingCentral&product=RingCX&language=en_US), destination types list. Checked 2026-09-25.
[^45]: For PSTN and SIP Route node destinations RingCX lets the admin set Caller ID (ANI, DNIS or a custom 10-digit number), Ring Duration, recording start/stop, music on hold, TT Accept, whisper and post-dial audio. Source: [Using the Route node in the RingCX Workflow Studio](https://support.ringcentral.com/article-v2/Using-the-Route-node-in-the-RingCX-IVR-Studio.html?brand=RingCentral&product=RingCX&language=en_US), PSTN and SIP settings. Checked 2026-09-25.
[^46]: Pointing a RingCX External phone or SIP Route node at a Unified CM phone or DN needs an internet-reachable SIP ingress in front of Unified CM, such as CUBE, that admits RingCentral's addresses and routes the call to Unified CM (inferred). Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Overview of Cisco Unified Border Element](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/voi-cube-overview.html), Overview of Cisco Unified Border Element. Checked 2026-09-25.
[^47]: A RingCX inbound queue has a Transfer Override Caller ID setting that sets the ten-digit number shown to recipients of calls transferred from that queue. Source: [Configuring inbound queue settings in RingCX](https://support.ringcentral.com/article-v2/Configuring-inbound-queue-settings-in-RingCX.html?brand=RingCentral&product=RingCX&language=en_US), General tab, Transfer Override Caller ID. Checked 2026-09-25.
[^48]: A RingCX voice channel lets customers reach the business by calling a RingCX phone number and routes those calls to a destination such as an inbound queue, a workflow or a cloud destination. Source: [Configuring a voice channel in RingCX](https://support.ringcentral.com/article-v2/configuring-a-voice-channel.html?brand=RingCentral&product=RingCX&language=en_US), introduction; destination section. Checked 2026-09-25.
[^49]: Numbers for RingCX voice channels are purchased or ported through RingEX and must be set up as CCRNs before use. Source: [Configuring a voice channel in RingCX](https://support.ringcentral.com/article-v2/configuring-a-voice-channel.html?brand=RingCentral&product=RingCX&language=en_US), prerequisites before configuration steps. Checked 2026-09-25.
[^50]: A RingCX voice channel is created in the RingCX Admin Portal under Channels > New channel > Voice, and it receives calls only while its Active box is checked. Source: [Configuring a voice channel in RingCX](https://support.ringcentral.com/article-v2/configuring-a-voice-channel.html?brand=RingCentral&product=RingCX&language=en_US), configuration steps; Active checkbox. Checked 2026-09-25.
[^51]: Cisco says a Unified CM route pattern can point directly to a gateway but recommends configuring route lists and route groups instead. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Call Routing](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_010010.html), section: Configure Route Patterns. Checked 2026-09-25.
[^52]: A voice class uri can match on host (hostname pattern, IPv4, IPv6 or DNS), user-id, or pattern (the entire URI string). Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), Information About Matching Inbound Dial Peers by URI; configuration task. Checked 2026-09-24.
[^53]: voice class uri patterns are case-sensitive and the pattern, user-id and hostname are limited to 32 characters. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), Restrictions for Matching Inbound Dial Peers by URI. Checked 2026-09-24.
[^54]: A voice class uri can contain at most 10 host ipv4/ipv6/dns entries in total and only one host hostname-pattern entry. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), Restrictions for Matching Inbound Dial Peers by URI. Checked 2026-09-24.
[^55]: Inbound dial-peer matching by URI works only for SIP (voip session protocol sipv2) and a dial peer can carry only one incoming uri match. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), Restrictions for Matching Inbound Dial Peers by URI. Checked 2026-09-24.
[^56]: incoming uri via matches against the topmost Via header, which identifies the last hop, and Cisco recommends it when the call traverses multiple SIP hops. Source: [Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards - Matching Inbound Dial Peers by URI of Incoming SIP Calls](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-inbnd-dp-match-uri.html), Information About Matching Inbound Dial Peers by URI (incoming uri via). Checked 2026-09-24.
[^57]: Checking Run on All Active Unified CM Nodes enables a SIP trunk on all cluster nodes. Source: [System Configuration Guide for Cisco Unified Communications Manager Release 15 and SUs - Configure Trunks](https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/15/systemConfig/cucm_b_system-configuration-guide-15/cucm_b_system-configuration-guide-14_chapter_01000.html), section: Configure SIP Trunks. Checked 2026-09-25.
[^58]: Cisco's basic debug set for SIP calls on CUBE is debug ccsip messages and debug ccsip error, with debug ccsip non-call optional, and debug voip ccapi inout recommended alongside because it usually has minimal CPU impact. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), SIP Call Flow Debugs; CCAPI debugs. Checked 2026-09-24.
[^59]: Before debugging, Cisco recommends logging to a 10 MB buffer (logging buffered 10000000), disabling console and monitor logging, and millisecond timestamps; debugs should be stopped (undebug all) if CPU exceeds 80%. Source: [Configure Debug Collection for CUBE and TDM Gateways](https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-border-element/215208-configure-debug-collection-for-unified-b.html), Configure > baseline logging configuration; CPU caution. Checked 2026-09-24.
[^60]: show call active voice brief shows, per call leg, pid:<peer_id> (the dial-peer tag used for that leg) and the direction Answer or Originate, which is how the matched inbound and outbound dial peers are confirmed for a live call. Source: [Cisco IOS Voice Command Reference - S commands - show aal2 profile through show call filter match-list](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/vcr4/vcr4-cr-book/vcr-s3.html), show call active voice > brief output format and field descriptions (Dial-Peer, CallOrigin). Checked 2026-09-24.
[^61]: Useful verification commands for this configuration include show dial-peer voice summary (operational status and keepalive), show voice class uri, show voice class dpg, show voice class server-group and show dialplan incall sip. Source: [Understand IOS and IOS XE Call Routing](https://www.cisco.com/c/en/us/support/docs/voice/ip-telephony-voice-over-ip-voip/211306-In-Depth-Explanation-of-Cisco-IOS-and-IO.html), verification examples (show dial-peer voice summary; show voice class uri). Checked 2026-09-24.
[^62]: CXone Integrated Softphone uses the WebRTC feature in the agent's Chrome browser to transmit voice. Source: [Telephony in NiCE CXone](https://help.nice-incontact.com/content/globalfeatures/connectivity/telephonyincxone.htm), section: Transport Options > Integrated Softphone. Checked 2026-09-25.
[^63]: CXone Integrated Softphone (WebRTC) needs outbound HTTPS port 443 and UDP ports 1024-65535 through the corporate and workstation firewalls. Source: [Connectivity Requirements](https://help.incontact.com/Content/PlatformRequirements/Ports.htm), table: Integrated Softphone (WebRTC). Checked 2026-09-25.
[^64]: When an agent uses Set Phone Number or a station with a Unified CM number, CXone places the agent leg as a call to that number, so the number must be reachable from the network CXone uses for the B leg (PSTN DID or a SIP path to Unified CM) (inferred). Source: [Telephony in NiCE CXone](https://help.nice-incontact.com/content/globalfeatures/connectivity/telephonyincxone.htm), sections: Transport Options > PSTN; VoIP Technologies > SIP (combined with Agent Workspace Voice Preferences). Checked 2026-09-25.
[^65]: In NICE CXone the portion of a call between CXone and the agent is called the B leg or agent leg, and it is the agent's audio connection to CXone for calls and voicemails. Source: [Connectivity in NiCE CXone](https://help.nicecxone.com/content/globalfeatures/connectivity/connectivityincxone.htm), section: A Leg and B Leg. Checked 2026-09-25.
[^66]: In NICE CXone a call transfer introduces a second B leg (agent leg). Source: [Connectivity in NiCE CXone](https://help.nicecxone.com/content/globalfeatures/connectivity/connectivityincxone.htm), section: A Leg and B Leg. Checked 2026-09-25.