Twilio Voice SDK lets you select the specific Twilio data center used when your
Call connects to Twilio. Network communication to and from Twilio will originate/terminate from the fixed, static IP address ranges listed below for each region. Refer to these ranges if you need to configure your local network to allow communication or apply Quality of Service routing rules to communication with Twilio.
By default, Programmable Voice SDK will use Twilio's Global Low Latency routing capability to determine which data center is closest to your user, establishing a connection through Twilio's nearest point of presence. Global Low Latency uses latency-based DNS lookups to determine the nearest data center. You may want to override this in some cases, especially when your users are working from a fixed location and using a DNS server in another region.
Global Low Latency uses latency-based DNS lookups to determine the nearest data center. We introduced setting a region in Voice SDK because there can be cases where the DNS address used by the App using Programmable Voice SDK may not represent their correct region. For example, if you are using a device in UK and the VPN server it is connected to is based in USA. If we relied on latency-based DNS lookups, the region Twilio will choose is going to be
"ie1" would have been preferred. Setting region on the caller side will guarantee the least latency in this scenario.
Force connections through Twilio Ireland:
TwilioVoice.region = "ie1";
Force connections through Twilio US East Coast region over your private Interconnect connection to that region:
TwilioVoice.region = "us1-ix";
Let Twilio choose the nearest region, skip setting the region.