Dual SIM Dual Active on iPhone

That reply muddies the issue. DSDS is not DSDA. The question is specific to DSDA which allows for simultaneous data over BOTH active (e)SIMs. The Qualcomm X70 modem found in iPhone 15 models support this feature and the newer X75 supports aggregation of two carriers data.

The DSDS implementation does not allow for a call on one carrier and continuing to use data on the other. See Qualcomm’s page on this feature for details: https://www.qualcomm.com/news/onq/2023/05/unleashing-full-potential-for-simultaneous-5g-cellular-connections-qualcomm-dsda-gen-2-with-dual-data

Apple would have to add support for DSDA or DSDAv2 into iOS. As a dual-SIM user for work and business, I have been waiting for this for years. We generally don’t speculate on future releases here, but I cannot see this being available in iOS until at least the next major release since I have not seen the behavior on my iPhone 15 Pro on iOS 17.1. I also found no mention of DSDA in iPhone specs or iOS 17 documentation. If someone finds something, please reply to let us know.

On iPhone 13 Pro and above models can have dual eSIM and both active. This uses Dual SIM Dual Standby (DSDS) technology, which means that both SIMs can make and receive calls.

Do you also have a Physical SIM? Then you can't. Note: You only have two IMEI numbers on your device.

To use two different carriers, your iPhone must be unlocked. Otherwise, both plans must be from the same carrier. If a CDMA carrier provides your first SIM, your second SIM won't support CDMA. Contact your carrier for more information. 

If you have an enterprise or corporate cellular service plan, check with your company administrator to see if they support this feature.