SIP Trunk Setup for Webex Calling

Use Voyced as an external SIP provider

This guide explains how to connect your Voyced telephone number and SIP service to Cisco Webex Calling.

Webex Calling is a cloud telephone system that allows users to make and receive business calls through the Webex app, compatible desk phones and other supported devices.

Unlike a traditional telephone system, Webex Calling cannot register directly with an external SIP provider using a SIP username and password.

To connect Voyced, use Webex Calling's Premises-based PSTN service and a supported Local Gateway.

The Local Gateway connects Webex Calling to Voyced and handles SIP registration, call routing, security and telephone number formatting.

This manual covers:

• Webex Calling and Control Hub

• Cisco Unified Border Element (CUBE) as a Local Gateway

• Webex registration-based and certificate-based trunks

• Connecting Voyced using SIP registration

• Incoming and outgoing telephone calls

• Telephone number assignment

• Caller ID and number formatting

• Testing and troubleshooting

The main example uses Cisco CUBE with a registration-based Webex Calling trunk.

What You'll Need

Before you begin, make sure you have:

• Administrator access to your Webex organisation

• Access to Cisco Webex Control Hub

• A Webex Calling subscription

• Suitable Webex Calling licences for your users

• A supported Cisco CUBE Local Gateway

• The required gateway licences and software

• A working internet connection

• Permission to manage PSTN connections, trunks and telephone numbers

• An active Voyced telephone number

Your Voyced SIP details:

Replace the example username and password with your actual Voyced service details.

Requirements Before You Begin

Understand the Connection

Webex Calling and Voyced use different SIP connection methods.

Your Local Gateway connects the two systems.

Webex Calling
      |
      | Secure SIP over TLS
      | Secure audio (SRTP)
      |
      v
Cisco CUBE Local Gateway
      |
      | SIP Registration
      | Username and Password
      | UDP Port 5060
      | Standard RTP Audio
      |
      v
  sip.voyced.eu
      |
      v
External Telephone Network

The Local Gateway performs several functions:

• Connects securely to Webex Calling.

• Registers with Voyced.

• Routes incoming and outgoing calls.

• Converts telephone number formats.

• Handles SIP identity information.

• Connects the audio streams between the two services.

The Two Separate SIP Connections

Your Local Gateway must establish two connections.

The credentials supplied by Webex and Voyced are different.

Do not use your Voyced password for the Webex Local Gateway connection.

Choosing a Local Gateway

Cisco supports two Local Gateway trunk types.

For a normal business installation using Cisco CUBE, the registration-based option is a suitable starting point.

Cisco CUBE supports separate SIP carrier registrations, allowing it to maintain the Webex connection and the Voyced connection.

If you use another SBC brand, such as a validated AudioCodes, Ribbon or Oracle product, use the certificate-based Webex trunk configuration.

Check the supported model and software version before configuring the connection.

SIP Trunk Setup Steps

1. Log in to Webex Control Hub

Open:

https://admin.webex.com

Log in using an administrator account.

Check that your organisation has Webex Calling enabled.

In Control Hub, you will manage:

• Locations

• Calling users

• Telephone numbers

• PSTN connections

• Local Gateway trunks

• Route Groups

• Calling features

The Local Gateway itself is configured separately using the administration tools provided by its manufacturer.

2. Check Your Webex Calling Licences

Navigate to:

Management → Users

Select a user who needs external calling.

Open the user's licence or service settings.

Confirm that Webex Calling is assigned.

For example:

Repeat this for each user who requires telephone calling.

A Webex Calling licence is different from a Cisco Calling Plan.

With Premises-based PSTN, Voyced provides the external telephone service through the Local Gateway.

You do not need to buy a Cisco Calling Plan merely to use this connection.

3. Check Your Webex Calling Location

Navigate to:

Management → Locations

Select the location that will use Voyced.

If the location does not exist, create it first.

Enter the required location information.

This may include:

• Location name

• Address

• Country

• Time zone

• Calling configuration

• Emergency services information

Each Webex Calling location uses a selected PSTN connection.

For this setup, choose Premises-based PSTN.

Do not change an existing working PSTN connection without reviewing which users and services currently depend on it.

4. Prepare the Cisco CUBE Local Gateway

Your Cisco CUBE must support Webex Calling Local Gateway functionality.

Before configuring the connection, check:

• Supported Cisco hardware or virtual CUBE platform

• Cisco IOS XE software version

• CUBE licence and session capacity

• Internet connectivity

• DNS resolution

• Network interface configuration

• Available SIP signalling and media resources

Cisco's registration-based Local Gateway requires a supported IOS XE version.

Use a Cisco-recommended software release for your platform.

The gateway must also support a separate SIP registration to Voyced.

Local Gateway Connections

The CUBE configuration should distinguish two connections:

Where the IOS XE version supports it, configure separate SIP tenants for these connections.

This keeps their authentication, transport and routing settings separate.

5. Create the Webex Calling Trunk

In Control Hub, navigate to:

Services → PSTN & Routing → Gateway configurations → Trunk

On organisations using the earlier Control Hub layout, the equivalent path is:

Services → Calling → Call Routing → Trunk

Click Add Trunk.

Enter:

For Cisco CUBE, select:

Registering

This creates a registration-based trunk between CUBE and Webex Calling.

The trunk name identifies the connection in Control Hub.

Click Save.

6. Record the Webex Registration Details

After saving the trunk, Control Hub displays the connection details.

These include:

• Register Domain

• Trunk Group OTG/DTG

• Line/Port

• Outbound Proxy Address

• SIP authentication username

• SIP authentication password

Record these details securely.

They are required when configuring the Webex-facing SIP connection on CUBE.

The registration domain and proxy address must come from your own Control Hub configuration.

Do not replace them with sip.voyced.eu.

That hostname belongs to the separate Voyced connection.

Webex Registration Example

If the password is lost, Control Hub provides an option to retrieve the username and reset the password.

Resetting the password requires updating the gateway configuration.

7. Configure CUBE Registration to Webex Calling

Open the Cisco CUBE administration interface or CLI.

Configure a SIP tenant for the Webex Calling trunk.

Use the information generated by Control Hub.

Cisco's registration-based Local Gateway connection uses TLS towards Webex Calling.

The standard Webex registration-based signalling destination port is 8934.

This differs from the common TLS SIP port 5061 used by many other systems.

Use the actual proxy hostname, port and registration parameters supplied by Control Hub.

Do not configure the Webex connection to use UDP 5060.

That is the destination port for the separate Voyced service.

Certificate Requirements

For registration-based Cisco CUBE connections, the gateway must trust the certificate authority used by Webex Calling.

A separate public SBC identity certificate is not normally required for the registration-based model.

Configure the trust certificates according to Cisco's Local Gateway instructions.

8. Verify Registration with Webex Calling

On Cisco CUBE, run:

show sip-ua register status

Check the registration associated with Webex Calling.

The registration should be active.

Return to Control Hub.

Navigate to:

Services → PSTN & Routing → Gateway configurations → Trunk

Open:

Voyced-LGW

Check the trunk status.

A working trunk should show that the Local Gateway is connected and available.

Cisco also uses SIP OPTIONS monitoring to check gateway availability.

Successful registration and a healthy trunk status confirm the connection between CUBE and Webex Calling.

They do not confirm the separate connection to Voyced.

9. Configure the Voyced SIP Connection

On Cisco CUBE, create a separate SIP carrier configuration for Voyced.

Use a dedicated SIP tenant where supported.

Enter:

The registrar must be:

sip.voyced.eu

The username must be your Voyced SIP account number.

For example:

442012345678

The password must be your Voyced service password.

The Voyced tenant must use these credentials rather than the Webex registration credentials.

10. Configure Voyced SIP Registration on CUBE

Cisco CUBE supports SIP trunk registrations using the IOS XE SIP tenant settings.

Relevant configuration elements include:

Configure the registrar as:

sip.voyced.eu:5060

Configure the SIP username:

Your-Voyced-DID

Use your actual password for the registration credentials.

Start with a requested registration expiry of 3600 seconds, if your configuration requires a value.

The SIP registrar may accept a different interval.

Separate SIP Tenants

If you use CUBE's tenant-based configuration, maintain separate tenant settings for Webex and Voyced.

The tenant used for Voyced must contain the Voyced registrar and credentials.

The tenant used for Webex must contain the Webex registrar and credentials.

Associate the appropriate tenant with the corresponding SIP dial-peers.

Cisco IOS XE command syntax and supported options depend on the platform and software release.

Use Cisco's CUBE multi-tenant configuration procedure for the exact commands supported by your gateway.

11. Verify Voyced Registration

On CUBE, run:

show sip-ua register status

Check the registration associated with Voyced.

You should see the registered Voyced account and its registrar.

Example:

Registrar: sip.voyced.eu
Username: Your-Voyced-DID
Status: Registered

This is an example of the expected information, not a literal copy of CUBE command output.

If the registration fails, review:

• SIP username

• Authentication username

• Password

• Registrar hostname

• SIP destination port

• UDP transport

• DNS resolution

Do not continue with inbound call testing until Voyced registration succeeds.

12. Configure the Outgoing Call Route on CUBE

The Local Gateway must send outgoing PSTN calls from Webex to Voyced.

Cisco CUBE uses dial-peers to select destinations.

Create or update the appropriate outbound VoIP dial-peer.

Configure:

The outgoing dial-peer must use the SIP credentials associated with Voyced.

It must also match the telephone numbers intended for external calling.

Avoid using an unrestricted dial-peer that allows unknown sources to make external calls.

The gateway should accept external calling requests only from the intended Webex connection.

13. Configure Outgoing Number Translation

Webex Calling normally uses E.164 telephone numbers with a leading +.

Voyced expects the same number without the leading +.

Example:

Create a called-number translation rule on CUBE.

The rule should remove the leading + before sending the SIP INVITE to Voyced.

Example

Original number:

+442012345678

Translated number:

442012345678

For a gateway supporting regular-expression-based number translation, the intended operation is:

Match:        + followed by international digits
Replacement:  International digits only

The final destination must contain the full country code and telephone number.

Do not remove the country code.

The exact Cisco translation-profile syntax depends on the IOS XE configuration.

Apply the translation to the outbound dial-peer towards Voyced.

14. Configure the Incoming Call Route on CUBE

The Local Gateway must also route incoming calls from Voyced to Webex Calling.

Create an incoming route associated with the Voyced SIP connection.

Then configure the outbound route towards Webex.

The gateway must identify incoming SIP calls as belonging to the registered Voyced connection.

It must also preserve the called telephone number.

If several DIDs are delivered through one Voyced account, the gateway needs to distinguish between them.

Do not replace every incoming called number with the primary registration username.

15. Configure Incoming Number Translation

Webex Calling uses E.164 telephone number formatting.

For example:

+442012345678

The standard Voyced destination format does not contain the leading +.

Configure CUBE to translate incoming called numbers when required.

Example

Number received from Voyced:

442012345678

Number sent towards Webex Calling:

+442012345678

The transformation is:

The exact translation depends on the incoming number format actually delivered to CUBE.

Inspect the incoming SIP INVITE before applying the rule.

If the number already includes +, it must not be added again.

16. Configure Audio and DTMF

The Local Gateway must handle media on both sides of the connection.

For Voyced, enable:

• G.711 A-law / PCMA

• G.711 μ-law / PCMU

Use G.711 across both sides when supported.

This avoids unnecessary transcoding.

If another codec is negotiated on the Webex side, the gateway may need transcoding resources.

Use the Cisco-recommended codec and media configuration for your Local Gateway deployment.

For keypad signalling, use RTP telephone events.

17. Configure Outbound Caller ID

Your outgoing calls must present a telephone number authorised for use with Voyced.

Webex Calling may send a caller ID such as:

+442012345678

The Local Gateway can convert this number to:

442012345678

when presenting it to Voyced.

Relevant SIP identity headers may include:

• From

• P-Asserted-Identity

• P-Charge-Info, where configured

For the first test, use your primary authorised Voyced telephone number.

Webex Dual Identity Support

When creating a Webex Local Gateway trunk, Control Hub provides a Dual Identity Support option.

This affects the handling of the From and P-Asserted-Identity headers.

For the initial setup, retain the default.

After confirming basic calling works, adjust the setting only if your organisation requires a particular caller ID or identity arrangement.

Make sure CUBE presents an authorised number towards Voyced.

18. Create a Webex Route Group

If you have one Local Gateway, you can assign its trunk directly to the PSTN connection.

If you have several gateways or want a separate routing object, create a Route Group.

In Control Hub, navigate to:

Services → PSTN & Routing → Gateway configurations → Route Group

Click Create Route Group.

Enter:

Save.

A Route Group can contain several trunks for redundancy or load balancing.

For a single-gateway installation, it will contain one trunk.

Do not add unrelated PBX trunks to the same group unless that is part of your intended PSTN routing configuration.

19. Select Premises-based PSTN for Your Location

Navigate to:

Management → Locations

Select the location using Voyced.

Open:

Calling

Find the PSTN connection settings.

Click Assign or Manage, depending on the existing configuration.

Select:

Premises-based PSTN (Local Gateway)

Choose the routing destination.

For example:

If you created a Route Group, select that group.

Otherwise, select the Voyced Local Gateway trunk directly.

Save.

Webex Calling will now use the selected Local Gateway for external PSTN calls originating from this location.

You do not normally need a separate Webex dial plan for ordinary PSTN calls when the location's PSTN connection already points to the Local Gateway.

20. Add Your Voyced Telephone Number

Navigate to:

Services → PSTN & Routing → Numbers

Click:

Manage → Add

Select the Webex Calling location.

Click Next.

Enter your Voyced telephone number.

For example:

+442012345678

Webex Calling uses E.164 formatting.

Enter each number using the format required for the selected country.

Click Save.

If your organisation has several numbers, they can be added together using comma-separated entries.

Confirm the numbers appear in the Numbers list.

21. Activate the Telephone Number

In Control Hub:

Services → PSTN & Routing → Numbers

Find the Voyced telephone number.

Check its activation status.

If the number is inactive and ready to use:

1. Open the number's actions.

2. Select Activate.

3. Confirm.

If the number is already active, continue.

The number must be active in Webex Calling and active on your Voyced service.

Activating a number inside Control Hub does not create a SIP registration with Voyced.

That registration is maintained separately by the Local Gateway.

22. Assign the Number to a User

Navigate to:

Management → Users

Select the user who should receive calls.

Open:

Calling

Find the user's number settings.

Assign an available Voyced telephone number.

Example:

Save.

The user should now have the telephone number assigned.

The Webex app or compatible telephone can receive calls directed to that number.

The user can also place outgoing calls through the configured PSTN connection.

23. Configure Your Location's Main Number

If your Webex Calling location requires a main number, assign one from the available telephone numbers.

Navigate to:

Services → PSTN & Routing → Numbers

Select the location.

Open the PSTN tab.

Find:

Main Number

Select the number to use as the location's main telephone number.

For example:

+442012345678

Save.

The location main number can also be used as an external caller ID for eligible users.

If the location contains trunks or extension-only users and services, Cisco requires an appropriate main number.

24. Configure an Auto Attendant

If your main Voyced number should answer calls with an automated menu, use a Webex Calling Auto Attendant.

Navigate to:

Services → Calling → Features

Find the Auto Attendant card.

Click Manage.

Create a new Auto Attendant or select an existing one.

Configure:

You can configure menu options such as:

Save.

Confirm the Auto Attendant has the correct active telephone number.

Test the menu by calling from an external telephone.

25. Configure a Call Queue

If several employees should answer incoming calls, create a Webex Calling Call Queue.

Navigate to:

Services → Calling → Features

Find Call Queue.

Create or select the required queue.

Configure:

• Queue name

• Location

• Telephone number

• Queue members

• Call distribution

• Business hours

• Overflow destination

For example:

Save.

Assign the intended telephone number to the Call Queue.

Incoming calls will then follow the configured queue rules.

26. Configure Additional Voyced Numbers

If several telephone numbers belong to one Voyced SIP account, they can share the same Local Gateway connection.

Example:

For each additional number:

1. Add the number in Control Hub.

2. Confirm it is active.

3. Assign it to the correct user or calling feature.

4. Check the incoming number translation on CUBE.

5. Test an incoming call.

The gateway must preserve the individual called number.

Separate Voyced SIP registrations are not normally required for additional numbers delivered through the same SIP account.

If you have several Voyced accounts with separate credentials, configure the appropriate additional carrier registrations on the gateway.

27. Check Outbound Number Routing

For normal external PSTN calls, Webex Calling sends the call to the PSTN connection selected for the user's location.

For this configuration:

Webex Calling User
        |
        v
Voyced-LGW
        |
        v
Cisco CUBE
        |
        v
sip.voyced.eu

The important routing requirements are:

• The user has Webex Calling enabled.

• The user's location uses Premises-based PSTN.

• The correct Local Gateway trunk or Route Group is selected.

• The Local Gateway is online.

• CUBE routes the destination to Voyced.

• CUBE removes the leading + from the destination number.

Example

User dials:

+442012345678

CUBE sends:

442012345678

to Voyced.

28. Configure Dial Plans Only Where Needed

Webex Calling also supports Dial Plans.

These are useful when your organisation has:

• An existing on-premises PBX

• Internal extension ranges

• Several connected telephone systems

• Special enterprise dialling requirements

Navigate to:

Services → PSTN & Routing → Gateway configurations → Dial Plans

Click Create Dial Plan.

Enter:

Do not create a broad dial plan that duplicates your normal PSTN routing.

For a straightforward Voyced connection without an additional on-premises PBX, the location's Premises-based PSTN connection is the main setting required for external calls.

29. Verify Call Routing in Control Hub

Webex Calling includes a routing diagnostic.

Navigate to:

Services → PSTN & Routing → Gateway configurations

Select:

Verify Call Routing

Choose the call source.

For example:

Cloud User

Enter the telephone number you want to test.

Example:

+442012345678

Click:

See Routing Result

Review the selected route.

Confirm that the intended Local Gateway or Route Group is used.

The diagnostic helps identify routing decisions before placing a real call.

It does not confirm Voyced SIP registration or RTP audio.

30. Configure Simultaneous Call Capacity

Your effective calling capacity depends on:

• Voyced service capacity

• CUBE licence and session limits

• Configured Webex Local Gateway capacity

• Any other traffic using the same gateway

Example:

These values are examples.

Use the actual capacity available on your service.

Cisco's registration-based Webex Local Gateway model supports up to 250 concurrent calls per trunk, subject to its supported platform and licence requirements.

Your Voyced service may have a lower capacity.

Configure the practical call limits accordingly.

31. Configure Firewall and NAT

Your Local Gateway must communicate with Webex Calling and Voyced.

Webex Calling Connection

For a Cisco CUBE registration-based trunk:

Cisco publishes the IP ranges and ports used by Webex Calling.

Use the current network requirements for your deployment.

Registration-based trunks can work behind dynamic NAT because the gateway initiates the secure connection.

Certificate-based trunks have different network and certificate requirements.

Voyced Connection

The RTP port range depends on your gateway configuration.

NAT Settings

If your Local Gateway is behind NAT, check:

• Public IP address handling

• SIP Contact addresses

• RTP media addresses

• Firewall session handling

• DNS resolution

• Both SIP registrations

Keep the Webex and Voyced SIP connections separate.

A successful Webex trunk registration does not guarantee that the separate Voyced SIP registration is working.

32. Configure Emergency Calling

Webex Calling supports emergency calling features.

These depend on the country, calling location and PSTN connection.

Review:

• Emergency service numbers

• Location address

• Emergency callback number

• Emergency call routing

• Any country-specific requirements

For locations requiring emergency calling, confirm that the intended provider route can support the service.

Do not assume a normal international call route handles emergency calls or provides the correct caller location.

Keep an existing approved emergency calling arrangement until any replacement has been tested.

Alternative: Certificate-based Local Gateway

If you use a validated third-party SBC rather than Cisco CUBE, use a certificate-based Webex Calling trunk.

33. Create a Certificate-based Trunk

In Control Hub:

Services → PSTN & Routing → Gateway configurations → Trunk

Click Add Trunk.

Enter:

The SBC must be reachable through its public FQDN.

The domain must be verified in Control Hub.

The gateway must have the required trusted certificate.

Configure the connection using the interoperability instructions for your SBC manufacturer.

34. Configure the Separate Voyced Connection

On the third-party SBC, create a carrier connection using:

Configure the necessary routes and number translations between the two connections.

The certificate-based Webex connection does not remove the need for SIP registration with Voyced.

Testing Your Setup

Webex Registration Test

For a Cisco CUBE registration-based Local Gateway:

1. Open Control Hub.

2. Navigate to the Local Gateway trunk.

3. Check its status.

4. Confirm the trunk is online.

5. Confirm SIP OPTIONS monitoring is working.

On CUBE, run:

show sip-ua register status

Confirm the Webex registration is active.

Voyced Registration Test

On the same gateway, check the separate Voyced registration.

The expected registrar is:

sip.voyced.eu

The registration should be active.

If one registration works and the other does not, troubleshoot the failing connection separately.

Outbound Test

1. Open the Webex app.

2. Select Calling.

3. Enter an international telephone number.

4. Place the call.

Example:

+442012345678

Webex sends the call to CUBE.

CUBE should convert the destination to:

442012345678

before sending it to Voyced.

Check:

• Correct Local Gateway selection

• Correct CUBE dial-peer

• Correct Voyced SIP tenant

• Successful SIP authentication

• Destination ringing

• Two-way audio

• Correct caller ID

Inbound Test

1. Call your Voyced telephone number from an external mobile telephone.

2. Confirm CUBE receives the incoming call.

3. Check the incoming called number.

4. Confirm the call is routed towards Webex.

5. Check the number is in the correct E.164 format.

6. Verify the assigned user or calling feature rings.

7. Answer the call.

8. Test audio in both directions.

Example:

Additional Tests

After basic calling works:

1. Test several simultaneous calls.

2. Test voicemail.

3. Test call transfer.

4. Test any Auto Attendant.

5. Test any Call Queue.

6. Test additional telephone numbers.

7. Review the call records.

Troubleshooting

Webex Calling Cannot Register Directly to Voyced

Webex Calling does not support directly entering Voyced SIP credentials as a normal external telephone account.

Use a supported Local Gateway.

The Local Gateway maintains the Voyced registration.

Webex Trunk Is Offline

Check:

• Webex registration credentials

• Control Hub registration domain

• Outbound proxy

• TLS connectivity

• SIP OPTIONS responses

• Firewall rules

• CUBE software and licence

• Trusted certificates

For a registration-based trunk, confirm that the gateway can establish the connection to Webex.

Voyced SIP Registration Fails

Check:

• Registrar is sip.voyced.eu.

• Username is correct.

• Authentication username is correct.

• Password is correct.

• Registration is enabled.

• UDP destination port is 5060.

• DNS resolution works.

The Webex credentials must not be used on the Voyced connection.

401 or 407 Error

These responses indicate an authentication challenge.

An initial challenge is normal.

If registration repeatedly fails, check:

• SIP username

• Password

• Authentication realm

• Registrar

• Subsequent authenticated REGISTER requests

403 Error

Check:

• Provider account status

• SIP authentication

• Caller ID authorisation

• Calling permissions

• Any account restrictions

Determine whether Webex or Voyced returned the error before changing settings.

404 Error

Check:

• Dialled number

• Number translation

• CUBE dial-peer

• SIP Request-URI

• Incoming DID matching

• Which system returned the response

Outbound Calls Do Not Reach CUBE

Check:

• Webex Calling licence

• User's location

• Selected PSTN connection

• Local Gateway trunk status

• Route Group assignment

• Call routing diagnostic

Use Verify Call Routing to check the selected route.

Calls Reach CUBE but Fail Towards Voyced

Check:

• Voyced registration

• Outbound dial-peer

• SIP tenant

• Number translation

• SIP authentication

• Caller ID

• Calling capacity

Confirm the final destination is digits-only.

Correct:

442012345678

Incorrect:

+442012345678

Incoming Calls Reach CUBE but Not Webex

Check:

• Incoming SIP identification

• Called number

• CUBE dial-peer routing

• Webex trunk status

• Incoming number translation

• Webex number assignment

The receiving number must match the number assigned in Control Hub.

All Incoming Numbers Reach One Destination

Check whether the Local Gateway preserves the actual called number.

Several Voyced telephone numbers may share one SIP registration.

CUBE must distinguish their individual DIDs.

Inspect the incoming SIP INVITE and the outgoing Request-URI towards Webex.

Incorrect Outbound Caller ID

Check:

• Webex user caller ID

• Location main number

• Dual Identity Support

• CUBE From header

• P-Asserted-Identity

• Number translation

• Authorised Voyced numbers

For the first test, use the primary Voyced number as caller ID.

One-Way Audio

Check:

• Webex SRTP connectivity

• CUBE media configuration

• Voyced RTP connectivity

• NAT handling

• Firewall rules

• Codec negotiation

• SDP media addresses

Successful SIP registration does not guarantee working audio.

Calls Disconnect Unexpectedly

Check:

• SIP ACK delivery

• TLS connection

• UDP session handling

• NAT

• Firewall timeouts

• Session timers

• RTP connectivity

Calls Fail After Transfer

Check:

• SIP REFER handling

• Re-INVITE handling

• CUBE dial-peers

• Number translation

• Caller ID handling

• Media renegotiation

Use Cisco's recommended Webex Local Gateway interoperability configuration.

Too Many Simultaneous Calls

Check:

• Voyced service capacity

• CUBE session licence

• Active gateway calls

• Configured call limits

On CUBE, you can inspect active calls using:

show call active voice brief

Reviewing CUBE SIP Logs

On Cisco CUBE, you can use:

show sip-ua register status

to check registration.

For SIP signalling troubleshooting, an administrator can use:

debug ccsip messages

For VoIP call routing:

debug voip ccapi inout

Repeat the failed call.

Review:

• REGISTER

• INVITE

• Request-URI

• From

• To

• P-Asserted-Identity

• SIP response codes

• SDP media information

• Incoming and outgoing dial-peer selection

Disable debugging after the test.

Remove passwords and authentication information before sharing SIP traces.

Registration Works but Calls Still Fail

Test the following separately:

1. Webex Local Gateway registration

2. Voyced SIP registration

3. Webex PSTN connection

4. CUBE dial-peer selection

5. Telephone number translation

6. Caller ID

7. Incoming DID assignment

8. RTP and SRTP audio

Final Tips

• Webex Calling cannot register directly with Voyced.

• Use Premises-based PSTN and a supported Local Gateway.

• Cisco CUBE supports registration-based Webex Local Gateway connections.

• Validated third-party SBCs use certificate-based Webex trunks.

• Keep the Webex and Voyced SIP credentials separate.

• Configure the Voyced registrar as sip.voyced.eu.

• Use your Voyced telephone number as the SIP username.

• Use your Voyced service password for authentication.

• Use UDP port 5060 on the Voyced connection.

• Use the Webex proxy and port supplied by Control Hub for the Webex connection.

• Enable G.711 A-law and G.711 μ-law towards Voyced.

• Configure incoming and outgoing call routes on the Local Gateway.

• Use E.164 numbers with a leading + inside Webex.

• Remove the leading + before sending calls to Voyced.

• Preserve the called DID when routing incoming calls.

• Assign each Voyced number to the correct Webex user or calling feature.

• Use an authorised outbound caller ID.

• Check emergency calling separately.

• Test both SIP connections, incoming calls, outgoing calls and audio.

Webex Calling supports external telephone providers through its Premises-based PSTN and Local Gateway services.

With a compatible gateway, the correct Webex configuration and successful Voyced SIP registration, your business can use Voyced for incoming and outgoing telephone calls through Webex Calling.

Last updated: 27/10/2026

© Voyced
All information provided is copyrighted and purely informative in nature. It is maintained by Voyced with the greatest of care using reliable sources only.
Given the fast evolution of the telecom sector, Voyced does not offer any guarantee about the accuracy and completeness of the information offered. 
We explicitly do not give anyone permission to use this information in any other way than to inform themselves about what (legal) requirements there may be and they need to comply with when registering Services and/or DIDs with Voyced.