Every apartment building will have a wifi? phone that would be able to be used by the tenant to make and receive calls on line 1 if they have a SIP? provider, and have the information that is needed. If this is applicable, the realty representative will login into the phone through their notebook PC, and will enter the credentials for line 1. The tenant can make and receive calls based on their plan that they set up with their provider.
If someone calls the building, they will be prompted to provide the extension number. Your apartment number is your extension. When someone dials your extension, they will ring the second line of the phone. They can carry a conversation just as if they called the number directly. You have unlimited incoming minutes. If the apartment has 3 and 4 number apartments (such as 901 vs 1001), then the caller must prepend a 0 to the 3 digit apartment number (such as 0901). A tenant can call another tenant and will display the appropriate apartment number as the caller. This is so no one can harass the neighbors.
When someone is in the public foyer, they will pick up the phone, and dial the apartment number. When this happens, line 2 on the WP810 will ring. If you wish to let the visitor in, you would press the * key (next to 0). The apartment number will have an option of receiving voicemails. Any voicemails will be emailed directly to the contact email address. This allows someone to leave a message without consuming valuable space with the telephony server.
As noted if you want to make calls from your apartment, you need to have a SIP account to the representative. Once that happens, you should be able to make calls as per your provider. Changing your plan should not change your settings. If you change your settings, then you would need to contact the realty company for making changes to the account. All external calls will display the telephone number provided by your SIP provider.