General requirements

For BYOC Cloud to work with a third-party carrier, the carrier must:

  • Be SIP-compliant*
  • Support the UDP, TCP, or TLS trunk transport protocol
  • Have a publicly routable IP address or host name

* Carriers must fully support Record-Routing as required by RFC 3261 to ensure proper routing of sequential SIP requests.

For more information, see the Genesys Cloud Carrier Interoperability Specification.

BYOC trunk requirements

SIP signaling IP addresses

The public SIP signaling IP addresses are the proxy IP addresses that Genesys Cloud BYOC trunks use to send and receive calls. Genesys Cloud load balances and uses any of the region’s IP addresses to send outbound calls. To allow SIP signaling traffic, you must add these IP addresses on the carrier-side ACL to your allowlist. 

Inbound calls to Genesys Cloud via BYOC can be sent at the network level to the following:

  • Any of the public SIP IP address or load balancer DNS names listed in the BYOC Cloud public SIP IP addresses article.
  • The trunk’s FQDN, as defined on the Genesys Cloud side. This FQDN always resolves to one of the public IP addresses. 

Note: Genesys Cloud handles call signaling and media using separate services for resiliency and scaling purposes. Genesys Cloud’s media services are autoscaling microservice instances, which are instantiated or removed as needed based on platform load. These instances draw IP addresses from a large pool of public addresses in AWS. For more information, see the Domains and IP Addresses section of the About ports and services for your firewall article.

URI configuration requirements for call routing and call request 

URI configuration applies to both inbound and outbound calls.

Inbound call routing

When configuring Inbound SIP routing for a BYOC Cloud trunk, Genesys Cloud requires a unique Inbound SIP Termination Identifier to be present in the INVITE to associate inbound calls with the appropriate Genesys Cloud Organization’s resources.

Note: The Inbound SIP Termination Identifier must be unique for your organization’s region.

You can choose one of four methods to format your inbound SIP INVITES.

  • FQDN (Fully Qualified Domain Name)
  • TGRP (Trunk Group Routing Protocol)
  • DNIS Replacement (Dialed Number Identification Service)
  • Inbound SIP Termination Header

By default you can use the recommended FQDN or TGRP method. If your carrier’s requirements prevent you from using either of those methods, you can enable the DNIS Replacement method.

To make it easy to understand how to format inbound INVITES , the Create External Trunk user interface provides you with dynamic help. When you begin typing an identifier in the Inbound SIP Termination Identifier box, the Inbound Request-URI Reference panel appears providing you with INVITE formatting examples that include your termination identifier and the address of your Genesys Cloud organization’s region.

The Inbound SIP Termination Header option provides you with the ability to specify a custom SIP header that is sent by the BYOC Carrier and contains the value you supply in the Inbound SIP Termination Identifier field.

Outbound call routing

Genesys Cloud also supports embedding a unique identifier in outbound INVITES. When you do, you can specify the INVITE to use either one or all available methods (FQDN, TGRP, or DNIS Replacement) using the Outbound SIP boxes. 

  • Outbound SIP Termination FQDN: Specify the domain portion of the Request-URI.
  • Outbound SIP TGRP Attribute: Specify the TGRP parameter of the Request-URI.
    • TGRP Context-ID: Specify the trunk context parameter of the Request-URI.
  • Outbound SIP DNIS: Specify the DNIS value for the outbound call attempt.

Again, you’ll find that the Create External Trunk user interface provides you with dynamic help. When you begin typing in one of the Outbound SIP boxes, the Outbound Request-URI Reference panel appears providing you with an INVITE formatting example that includes the identifier values that you enter.

For more information, see Configure SIP routing for a BYOC Cloud trunk.

FQDN routing method for inbound calls 

When you configure the Genesys Cloud side of a BYOC trunk, you specify a trunk-specific value. Genesys Cloud uses this value as a unique identifier to properly route inbound calls to the correct Genesys Cloud organization’s resources. This value is prepended to the region’s BYOC trunking domain. The result is a unique, resolvable trunk FQDN.

For example, if the region’s BYOC trunking domain is .byoc.mypurecloud.ie, and the unique identifier is myuniqueidentifier, then you would format the Request-URI as:  

sip:+13172222222@myuniqueidentifier.byoc.mypurecloud.ie

TGRP routing method for inbound calls  

If FQDN does not work as the Request-URI in your environment, Genesys Cloud also supports using the Trunk Group Routing Protocol (TGRP) for inbound calls. You use the same unique identifier, but instead of placing it in the domain portion of the Request-URI, you incorporate it into the TGRP-specific attributes.

For example, if the region’s BYOC trunking domain is .byoc.mypurecloud.ie and the unique identifier is myuniqueidentifier, then you would format the Request-URI as:

sip:+13172222222;tgrp=myuniqueidentifier;trunk-context=byoc.mypurecloud.ie@<Domain>

Where Domain would be either one of the region’s IP addresses or one of the load balancer DNS names. See BYOC Cloud public SIP IP addresses.

DNIS Replacement routing method for inbound calls

If your carrier’s requirements prevent you from using either the FQDN routing method or the TGRP routing method for inbound calls, you can enable the DNIS Replacement method.

When you use the DNIS Replacement method, Genesys Cloud inspects the DNIS portion of the inbound Request-URI for the trunk’s unique identifier. In this case, Genesys Cloud only uses the DNIS for Org and trunk identification. After it identifies the Org and Trunk, Genesys Cloud routes based on the address in the TO header.

For example, if the region’s BYOC trunking domain is .byoc.mypurecloud.ie, and the unique identifier is myuniqueidentifier, then you would format the Request-URI as:

sip:myuniqueidentifier@lb01.byoc.mypurecloud.ie