Different VoIP Phone service prividers offer different  call features, and same provider may office different call features with different plans.ome features are free with the account, some features are not free. You need to check and compare the call features when you choosing your voip providers.

Caller ID :(Call Display) shows an incoming caller’s name and telephone number (if available) on a caller ID-equipped phone or caller ID unit before you answer the call.

Call Forwarding : With Call Forwarding, you can redirect incoming  calls to another phone, mobile or landline number

Call Waiting : With Call Waiting, you’ll know if another call is coming in when you’re already on the line. And if you have a caller ID phone, the names and numbers of incoming calls will be displayed when you are on the phone. you can put the current on hold and answer second call.

Call Transfer : Call Transfer lets you direct a live call to another phone number

Call Return : you can dial the last number that called you whether you answered the call or not.

3-Way Calling : The 3-Way Calling feature lets you talk with two other people in one call.

Call Blocking : gives a  subscriber the option to block all calls to his or her telephone. Callers automatically receive the personalized greeting and are given the option to leave a message.

VoiceMail : service that will take voice messages for you if you are unable to answer a call,The phone alerts you to indicate the receipt of a message.

Do not Disturb : With the do not disturb feature, you can block all calls and decide what to do with them. The options are: send them to voicemail, drop the call with a message, or drop the call without a message.

Call Hunting : Set a path for unanswered calls to follow in case you are on the phone or away from your main phone.

Last Number Re-dial :  By pushing a button, you can redial the last number you called, thus saving yourself from having to dial the number again.

411 Directory Service :  A phone assistance number which you call to get phone numbers and other information about businesses and people over your area.

Local Number Portability :  Use your existing phone number with VoIP , Port your existing Landline PSTN phone number to your VoIP Phone.

911 Service :  911 is US and Canada emergency service, the equivalent of 112 in the European Union.

E911 Service : enhanced version of the 911 emergency service , This service is being included into VoIP packages,  If you change address, make sure you update it with your provider. If you use your VoIP service while on the move, then E911 might not be very helpful as they only have a fixed address to locate you. 

Change Phone Number: Change your phone number without changing service provider.

Anonymous Call Rejction :  Rejecting  anonymous calls(Caller number is not displayed, or displayed as "private number") .

PC to Phone Option (Softphone):  make calls using a softphone installed on your computer.  

Area Code Selection :  rea Code Selection allows you to select an area code of your choice to attach to your phone number.

Contact Lists :  allow you to customize your Caller ID so that the name displayed for a contact is the one that you want to see.

Enhanced Voicemail : Enhanced voicemail is voicemail a step further - integrated with other technologies. With the enhanced voicemail feature, you can listen to your voicemails over the Internet using the web interface of your VoIP service provider; listen to your voicemails from any other phone; or receive your voicemails as email attachments, and more..

Line Unavailable Forward :  If your VoIP phone line unavailable, the call can be forwarded to any other number of your choice.

Repeat Dial if Busy :  When you dial a number and hear the busy tone, the 'repeat dial if busy' feature will automatically redial the number time and again,Redialing will continue until the recipient's line is free.

Call Transfer :  transfer the call directly to another phone number.

Call Return :  allows you to call back the number whose call you missed by simply pressing some buttons (like *69). You don't even need to know who called or who their number is.

Speed Dialing :  allows you to dial your most frequent contacts by pressing only one or two digits.

Distinctive Ringing :  allows you to set different ringing tones for different numbers in your contact list.

Multi-Ring :  feature allows you to set more than one phone to ring whenever there is an incoming call. You can have your home phone, cell phone, office phone and any other phone to ring at the same time when someone calls.

Caller ID Blocking:  Caller ID blocking allows you to hide your name and number when you can someone.

Do Not Disturb :  With the 'do not disturb' feature, your phone will not ring.  The person calling will be prompted to leave a voicemail, which you will retrieve when you are ready for it.

International Blocking :  allows you to block and unblock international calls from your phone line.

Travel Globally :  allows your friends and family to contact you over your VoIP phone number wherever you are in the world, without them having to pay high international rates.

Unlimited to US/Canada :  With this feature, however much you talk to people within the US and Canada, you pay a same flat amount, without additional costs.

Extra Virtual Numbers : An extra virtual number is another phone number which you can add to your existing phone line. This way, you can have one phone line with more than one number on it.

Toll Free Numbers : your service provider can get you toll-free numbers. , anyone in your country can call you for free calling to this toll free number.

SMS ( Short Message System ):  send SMS using VoIP phone . 

Online Account Management : allow you to check and manage your account online via web site.