Voice IP Migration Schedule Update

Based on your feedback, we're extending the Twilio Voice IP migration timeline from October 10, 2023, to a new 100% traffic migration date of January 23, 2024.

Before this new migration date, we'll perform two days of testing with limited traffic:

• December 5, 2023: 1% of all calls will use the new range for 24 hours
• January 16, 2024: 20% of all calls will use the new range for 24 hours

We won't migrate traffic on the previously communicated dates of September 26, October 5, or October 10, 2023.

NOTE: Customers using Twilio Interconnect for Elastic SIP Trunking, Flex, Programmable SIP, SIPREC, or Voice SDKs calls are being migrated in a separate migration with a different timeline as communicated here.

Based on the volume of requests for deadline extensions we received, we understand you need more time to complete the necessary changes. This extension gives you additional time to allowlist the full IP/port ranges, place test calls, and opt-in your production traffic before the migration.

Before December 5, 2023, make sure you, or your networking engineering or operations teams, are informed of this change updates your network infrastructure to allowlist the full IP and port ranges following the steps below:

1. Add 168.86.128.0/18 to your firewall rules.
2. Enable UDP from these IP addresses over ports 10000-60000.

Then, place test calls for your Twilio application using one of these methods:

• Enable your accounts to use the new ranges for all Voice product traffic. Then, during a maintenance window or other low-traffic period, use a testing subaccount or production account to test calls, verifying successful call setup and two-way audio.
• Test Voice SDK and Flex calls using Twilio's Network Test tool; it now has an option that uses the new IP and port ranges. This tool tests both call setup and two-way audio.

Once you've updated your network infrastructure and successfully tested, enable your account's production traffic to use the new IP ranges. You don't need to wait for the limited traffic testing dates or final migration date.

If you don't opt your production traffic into using the new IP/port ranges, you'll still need to keep the old IP and port ranges open in your infrastructure until January 23. 2024; these ranges won't be able to accept or send traffic after this time, but they need to stay open until you have opted your account in, or the migration is complete.

There are three upcoming dates with escalating potential consequences:

• If you don't take action by December 5, 2023, you'll experience one-way audio and dropped calls for 1% of all calls placed on that date.
• If you don't take action by January 16, 2024, you'll experience one-way audio and dropped calls for 20% of all calls placed on that date.
• If you don't allowlist the full IP and port ranges before the migration, all calls will fail after January 23, 2024.