There is a specific VoIP regulatory need for businesses in India. While there are no restrictions for calls made within an organization using a private IP network, there are specific regulations such that PSTN connection must be used when connecting calls outside enterprise. According to the Telecom Regulatory Authority (TRAI) regulations, the PSTN telephony network in India must never be interconnected with the VoIP Telephony network for Toll Bypass. There are more data retention requirements for Other Service Provider (OSP) customers that they must maintain call data records and system logs for one year.


  • Webex Calling Location: The location that is set up in the Control Hub for Webex Calling.

  • User’s Physical Location: The physical location of the calling user. For example Office, Cafe, and Home.

To comply with the regulations, Webex Calling has implemented administrative controls that route calls based on a user’s physical location. An administrator associates IP subnets to a location in Webex Calling to determine the user’s physical location. At the time of PSTN interconnect, if a user’s endpoint IP address matches one of the configured subnets, then a user is internal to the enterprise network.

Outbound and inbound PSTN calls are allowed for internal users. If the user’s endpoint is outside the configured subnet, that means user is roaming. PSTN interconnects restrictions apply for roaming users.

To be compliant with these regulations, you must follow specific instructions to configure Webex Calling locations in India. This article explains how to add Webex Calling locations for enterprises in India, and to create and configure a trunk for a PSTN connection for each Webex Calling location in India.

You can use the following diagram as a helpful visual, while walking through the steps:

Before you begin, let’s define some key terms:

  • Trusted Network Edge: Collection of IP addresses that represents edge breakout node(s). Create trusted network edges at the organization level up to a maximum of 1,000 per organization.

  • Zone: Collection of IP addresses that represent devices or users behind an edge. Create zones at the organization level up to a maximum of 1,000 zones per organization. Multiple zones can share the same network edge.

  • Location: A Webex Calling location in India that needs a PSTN connection, must have a zone assigned to it. If you do not assign a zone to a Webex Calling location with a PSTN connection, then toll bypass restrictions do not apply to the Webex Calling location. Multiple Webex Calling locations can share the same zone. All users, workspaces, features (such as auto attendants), and trunks within a Webex Calling location use the Webex Calling location’s zone.


You cannot assign zones to Webex Calling locations outside of India. Presently this configuration can not be done in Control Hub. The Cisco operations team will help with the configuration until the settings are made available in Control Hub.

To add a new Webex Calling location, make sure you have the location address ready. For more information on adding a Webex Calling location in India, see: Add a location.


Premises-based PSTN (local gateway) is the only option for a location in India.

Once you add a Webex Calling location, and before you configure premises-based PSTN for a Webex Calling location, you must create a trunk.

Before you create a trunk, review the following requirements specific to route groups and PSTN connection interactions for Webex Calling locations in India:

  • All trunks in a route group must belong to the same zone (including zones not associated to a Webex Calling location).

  • When a location’s PSTN connection is set to premises-based PSTN, the selected trunk or route group must belong to the same zone (including no assigned zone) as the Webex Calling location.

If you need to change the Webex Calling location’s zone, make sure to consider the following:

  • If there are route groups using trunks in Webex Calling location and other locations, the zone is rejected. Change the route group first so that only trunks in the same zone belong to it.

  • If there are other Webex Calling locations using trunks from this Webex Calling location as their PSTN connection directly or through a route group, it rejects the changes to the zone. Change the other locations Route Group so that they do not use Webex calling location for which zone change is intended.

  • If the PSTN connection for this Webex Calling location is using the trunk or route group from other Webex Calling locations, the changes to the zone are rejected. To use the Webex Calling location, change the PSTN connection or route group first so that trunks or route group.

For more information on creating a trunk, see: Configure Webex Calling for your organization.

Here are examples of call scenarios where users are in a Webex Calling location with a zone and trusted network edge that illustrate how to prevent toll bypass. In these examples, consider the following:

  • Webex Calling zone: A location in India that is set up with a zone and trusted network edge.

  • Outside Webex Calling zone:

    • Webex Calling location in India that is set up with a different zone and trusted network edge.

    • Webex Calling location that is not set up with a zone and trusted network edge.

  • Roaming: User, who is outside the organization, for example, a user working from home.


The term endpoint in the following examples refers to the user’s desk phone or Webex App.

Webex Calling user places an outbound call to PSTN

The network location of user’s endpoint determines how a call is routed when a Webex Calling user calls a PSTN user:

Network location of endpoint

Routing of outbound call

User’s endpoint is in a Webex Calling zone.

Call routes using a PSTN connection are set up for that zone’s location.

User’s endpoint is roaming.

PSTN calling is not possible.


 

Users can use Webex Calling’s call back feature to call PSTN users.

Webex Calling user receives an inbound call from PSTN

The Webex Calling user’s endpoints must be inside the organization’s premises to receive inbound calls from PSTN users. If there are OSP organizations, then the remote agent can connect to the enterprise network using a VPN to be in the zone.

For calls that do not route to the user’s endpoint, the administrator can set call forward not available settings. For example, the call forward settings can be set up to route calls to voicemail.

Network location of endpoint

Routing of inbound PSTN call

User’s endpoint(s) are inside the Webex Calling zone.

Call routes to the user’s endpoint.

User’s endpoint(s) are roaming.

Call does not route to the user’s endpoint.

Webex Calling user transfers or forwards incoming PSTN call to another Webex Calling user

There is no limitation to transfer or forward calls between Webex Calling users. However, there are limitations to transfer or forward calls to a user in the India PSTN network. The general rule is that transfer and redirect of an incoming PSTN call to a user in the same Webex Calling zone as the transferring or forwarding user is allowed and is restricted to a user in a different Webex Calling zone.

The following table shows whether call transfer and call forward are allowed or restricted:

Endpoint location of target user

Call transfer

Call forward

Is in same Webex Calling zone as the user that is transferring or forwarding.

Call transfer is successful.

Call forwards to the other user.

Is in different Webex Calling zone as the user that is transferring or forwarding.

Call transfer is unsuccessful.

Call forward is unsuccessful.

Is roaming.

Call is not transferred to roaming endpoints.

Call is not transferred to roaming endpoints.

Webex Calling user transfers or forwards calls to a PSTN user in India

Transferring and forwarding an inbound VoIP call from another Webex Calling user to the PSTN must honor the toll bypass restrictions for both the caller and called users.

The following table shows how toll bypass affects the routing of a call initiated by a Webex Calling user to another Webex Calling user who transfers or forwards the call to a PSTN endpoint in India.

User initiating transfer or forward

Transfer to PSTN

Forward to PSTN

Is in same Webex Calling zone as the calling user.

Transfer is successful.Uses the PSTN connection of the transferring user's Webex calling location.

Call forwards to the PSTN; Uses the PSTN connection of the forwarding user's Webex calling location.

Is in different Webex Calling zone as the calling user.

Call transfer to the PSTN endpoint is unsuccessful.

Call forward to the PSTN endpoint is unsuccessful.

Is roaming.

Consult call transfer to the PSTN endpoint is unsuccessful.

Call is forwarded if calling user is in same location as forwarding user, else the call is not forwarded.

Webex Calling user conferences a PSTN user

The conference that includes a Webex Calling user on VoIP and one or more PSTN endpoints must honor the toll bypass restrictions. The following table shows how toll bypass affects the 3-way/N-way conference feature in Webex Calling.

Initial call before conference

User initiating conference

Conference with PSTN endpoint

Both users’ endpoints are in the same Webex Calling zone.

User 1 initiates a conference to a PSTN endpoint.

Attempt to escalate to conference is successful.

Both users’ endpoints are in different Webex Calling zones.

User 1 initiates a conference to a PSTN endpoint.

Attempt to escalate to conference fails.

User 1 who is in a Webex Calling zone is in active call with a roaming user.

User 1 initiates a conference to a PSTN endpoint.

Attempt to escalate to conference fails.

Single Number Reach (Office Anywhere)

With this feature, an incoming call to a Webex Calling user simultaneously rings on the user’s PSTN endpoint. To prevent toll bypass, the geographic location of the calling party and the Webex Calling location of the called party is analyzed to determine whether to route the call to the PSTN endpoint.

The routing behavior when a Webex Calling user in a geographic location makes a VoIP call to a user in a different Webex Calling location with a single number reach set to a PSTN endpoint.

Called user Webex Calling Zone

Single Number Reach (SNR) target

Is same as the Webex Calling user.

The PSTN endpoint alerts simultaneously, uses the PSTN connection of the user's Webex calling location that has configured Single number reach/office anywhere.

Is different than the Webex Calling user.

The PSTN endpoint does not alert simultaneously.

Inbound calls to call queue, hunt group, or auto attendant

PSTN callers can connect to users in a call queue, hunt group, or auto attendant. Once the user answers the in-call queue, hunt group, auto attendant, the call transfers to users within the same Webex Calling zone as the user who answered the call.

Executive-Assistant

When you configure the Executive-Assistant feature, it is recommended that both the executive and assistant are set up in the same Webex Calling zone.

If an admin has configured a pool of assistants for an executive and some of the assistants are in a different Webex calling location with a zone that is different than the zone of the executive, then the following rules apply:

  • For an inbound call from a PSTN endpoint, the assistant's endpoint is not alerted.

  • Assistant cannot make outbound PSTN calls on behalf of the executive.

Many organizations in India use the Extend and Connect feature with Unified CM calling, which enables their users to call PSTN users while they are roaming (for example when working from home). This feature is also available to Webex Calling users on the Webex App. Calls in the user’s Webex Calling business number do make it to PSTN using the call back feature. For more information on the call back feature, see: Webex App | Make work calls using Call Back.

India regulations require that the administrator of an OSP center has their CDR files on a local server for one year. Webex allows CDR field to access and download in the Control Hub. To download CDR files, see: Reports for Your Cloud Collaboration Portfolio

  • Attempts to call a PSTN number or receive a call from a PSTN number, when the user is roaming to a different enterprise location than their assigned enterprise location is not currently supported.

  • For organizations that use a centralized VPN, the users appear to come in the centralized VPN gateway’s network location. The system is unable to detect the user's actual geographic location and hence the toll bypass policies do not apply accurately.

  • The setting Call routing between Webex Calling and premises must be set to “Standard” for correct toll bypass policy for inbound calls routing if an organization has Webex Calling locations in India.

  • A Webex Room Device not registered natively to Webex Calling is set as not inside the enterprise network and hence roaming policies apply.

  • Audit logs available from Control Hub do not include data on provisioning changes that are made to Webex Calling.

  • The endpoints with IPv6 addresses are not supported.

  • For any integration with on-premises Unified CM, users are always considered to be roaming, and roaming restrictions apply.