conference call on iPhone

Perhaps you'd like to elaborate a bit... iPhones are technically capable of conference calling. That feature requires carrier support. Different carriers support varying numbers of simultaneously connected calls...

What, exactly, are you asking?

ith GSM, you can set up a conference call with up to five people (depending on your carrier).

Note: Conference calls may not be available if your call is using VoLTE (Voice over LTE).

Create a conference call. While on a call, tap Add Call, make another call, then tap Merge Calls. Repeat to add more people to the conference.

• Drop one person: Tap next to a person, then tap End.
• Talk privately with one person: Tap , then tap Private next to the person. Tap Merge Calls to resume the conference.
• Add an incoming caller: Tap Hold Call + Answer, then tap Merge Calls.

This is as per the iOS 10 manual:

http://help.apple.com/iphone/10/#/iph3c99551d