Configuring Multi-Region BYOC Cloud Trunks with Automated Failover

How-To-Articles
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Configuring Multi-Region BYOC Cloud Trunks with Automated Failover

Executive Summary & Architectural Context

For global enterprises, relying on a single SIP trunk in a single geographic region is a catastrophic single point of failure. If an underwater fiber cable is cut in the Atlantic, or an AWS region experiences a massive outage, your entire contact center goes dark.

Genesys Cloud Voice provides native redundancy, but many enterprises choose Bring Your Own Carrier (BYOC) Cloud. In BYOC Cloud, you terminate your carrier’s SIP trunks directly into the Genesys Cloud AWS infrastructure over the public internet or AWS Direct Connect.

To achieve 99.999% uptime, you must architect a Multi-Region Active/Active trunking topology. This masterclass details how to configure primary and secondary BYOC Cloud trunks across different AWS regions (e.g., us-east-1 and us-west-2), map inbound DID routing, and engineer automated outbound failover logic using Genesys Cloud Outbound Routes.

Prerequisites, Roles & Licensing

  • Licensing: Any Genesys Cloud CX tier with BYOC Cloud enabled.
  • Roles & Permissions: Telephony > Trunk > Add/Edit, Telephony > Site > Edit.
  • Platform Dependencies:
    • A Tier 1 SIP Carrier capable of routing DIDs to multiple geographic endpoints (e.g., Twilio, Bandwidth, Verizon).

The Implementation Deep-Dive

1. Creating the Regional BYOC Trunks

You must establish two distinct SIP trunks inside Genesys Cloud, anchored to two different AWS regions.

  1. Navigate to Admin > Telephony > Trunks.
  2. Click Create New. Type: BYOC Cloud.
  3. Trunk 1 (Primary):
    • Name: CarrierA_US_East
    • Region: Select us-east-1 (Virginia).
    • Define the Inbound/Outbound SIP URIs and TLS/SRTP security profiles.
  4. Trunk 2 (Secondary):
    • Name: CarrierA_US_West
    • Region: Select us-west-2 (Oregon).
    • Note: Ensure your carrier assigns a different Source IP or FQDN for the West coast handoff to prevent asymmetric routing loops.

2. Inbound Failover (Carrier-Side Routing)

Genesys Cloud cannot control inbound failover; the call hasn’t reached the platform yet. You must configure this logic in your carrier’s portal.

  1. Log into your Carrier’s routing portal (e.g., Twilio Console).
  2. Locate the SIP Trunk configuration for your toll-free numbers.
  3. Primary Route: Point all inbound SIP INVITEs to the Genesys Cloud us-east-1 FQDN (e.g., your-org.byoc.cac1.pure.cloud).
  4. Failover Route: Configure a SIP 503 Service Unavailable or 408 Request Timeout trigger. If the East Coast Genesys edge does not respond within 2 seconds, the carrier must automatically attempt the us-west-2 FQDN (e.g., your-org.byoc.usw2.pure.cloud).
  5. Because both trunks are registered to your single Genesys Cloud Org, the call will seamlessly drop into the exact same Inbound Call Flow regardless of which region received it.

3. Outbound Failover (Genesys-Side Routing)

When an agent makes an outbound call, Genesys Cloud controls the routing. You must configure Architect to try the East trunk, and if it fails, try the West trunk.

  1. Navigate to Admin > Telephony > Outbound Routes.
  2. Create a new route: Global_Outbound.
  3. Pattern Match: ^+1[2-9]\d{9}$ (Standard North American 10-digit dialing).
  4. Trunks Configuration:
    • You can assign multiple trunks to a single route.
    • Add CarrierA_US_East.
    • Add CarrierA_US_West.
  5. Distribution Strategy:
    • Sequential: Genesys will always try the East trunk first. If the carrier returns a 503 or timeout, Genesys will instantly retry the call out the West trunk. This ensures East is the primary.
    • Random/Round Robin: If you want to load-balance traffic 50/50 across both coasts to ensure both pipes remain “warm”, select Random.

Validation, Edge Cases & Troubleshooting

Edge Case 1: SIP Options Ping (Keepalives)

If the East Coast trunk goes down, you don’t want Genesys Cloud to attempt to send 500 outbound calls to it, wait for 500 timeouts, and then failover. That introduces a 2-second delay to every call setup.

  • Solution: You must enable SIP OPTIONS Pings on both BYOC trunks in Genesys Cloud.
  • Genesys Cloud will send a SIP OPTIONS message to the carrier every 60 seconds. If the carrier stops responding to the ping, Genesys Cloud instantly marks the CarrierA_US_East trunk as Out of Service. The Outbound Routing engine will immediately bypass it and send all traffic to the West trunk with zero latency penalty for the agent.

Edge Case 2: Media Tromboning (Latency)

If an agent sitting in an office in New York makes an outbound call, and the Outbound Route sends the call out the us-west-2 (Oregon) trunk due to a load-balancing configuration, the RTP audio stream must travel from NY → Oregon → Carrier → Destination. This introduces 80ms+ of unnecessary latency.

  • Troubleshooting: For highly distributed workforces, you should tie Outbound Routes to specific Sites.
  • Solution: Create a New_York_Site and an Oregon_Site. Assign the East Trunk as the primary for the NY Site, and the West trunk as primary for the Oregon site. Only use cross-country trunks as emergency backups, never as standard round-robin load balancers.

Official References