Known limitations in Azure telephony

This article provides information about limitations and known issues related to telephony in Azure Communication Services.

Azure Communication Services direct routing known limitations

Maximum number of configured Session Border Controllers (SBC) is 250 per communication resource.
When you change direct routing configuration (add SBC, change Voice Route, etc.), wait approximately five minutes for changes to take effect.
If you move SBC FQDN to another Communication resource, wait approximately an hour, or restart SBC to force configuration change.
Azure Communication Services SBC Fully Qualified Domain Name (FQDN) must be different from Teams Direct Routing SBC FQDN.
One SBC FQDN can be connected to a single resource only. Unique SBC FQDNs are required for pairing to different resources.
Media bypass/optimization isn't supported.
Azure Communication Services direct routing isn't available in Government Clouds.
Multitenant trunks aren't supported.
Location-based routing isn't supported.
No quality dashboard is available for customers.
Enhanced 911 isn't supported.
In-band Dual-tone multi-frequency (DTMF) isn't supported. Use RFC 2833 DTMF instead.
Multiple IP addresses mapped with the same FQDN on the SBC side aren't supported.
Maximum call duration is 30 hours.
Early media isn't supported for group calls.