You can use different methods to turn on these features, depending on your wireless operator's network technology (GSM or CDMA):
| Feature | iPhone (GSM networks) | iPhone (CDMA networks) | Notes |
|---|---|---|---|
| Call forwarding | Turn on or off in Settings > Phone. |
Contact your operator for information on using Call Forwarding. | To see if call forwarding is turned on, look for this icon  in the status bar. |
| Call waiting | Turn on or off in Settings > Phone. |
Contact your operator for information on using Call Waiting. | |
| Caller ID | Turn on or off in Settings > Phone. |
Contact your operator for information on using Caller ID. | |
| Conference calls | Supports up to five calls simultaneously | Supports up to two calls simultaneously. | CDMA networks may not be able to add, swap or merge calls in certain situations. VoLTE may prevent certain features of Conference calling. See the iPhone user guide for more details |
| Dial a soft pause | Tap and hold * when you dial. When you edit a contact number, tap +*#, then tap 'pause'. | Inserts ',' into a phone number and waits a few seconds before dialling the additional digits. | |
| Dial a hard pause | Tap and hold # when dialling. When editing a contact number, tap +*#, then tap 'wait'. | Inserts ';' into a phone number and waits for the user to tap Dial before dialling the additional digits. | |
| Place a call on hold | Tap and hold Mute. | N/A | You can't place a call on hold on CDMA networks. |
- Learn more about differences using mobile data networks, including LTE.
- Detect and block spam phone calls with third-party apps.
- Block phone numbers and contacts or filter messages on your iPhone, iPad or iPod touch.