Sometimes incoming calls need to be treated differently: calls from your boss or secretary should reach you on your cell phone even during the weekend, while other calls can just go to voicemail. Calls in the evening hours should go straight to your cell phone (there is no point in ringing your IP phone while you are not in the office), while calls from your ex-girlfriend should always go to voicemail.
All of this can be done using the call screening rules in PortaSwitch. When the call screening feature is enabled for an account (phone line), you can define a set of rules that will be applied to every incoming call. Each rule may include some of the following limitations:
- From – calling number condition. You can specify a list of phone numbers for a caller (ANI or CLI) which satisfy this condition, e.g., you can list extensions for your boss and secretary, your home phone, your wife’s cell phone number, and so on. When specifying a phone number, you can enter either the full number or a pattern (e.g., all numbers starting with 1800).
- To – called number condition. This can be useful if you have multiple account aliases (or DID numbers) forwarded to your main account. For instance, you may wish to treat incoming calls to your business toll-free number differently from calls to your regular phone number.
- Time Window – call time condition. You can specify limitations regarding the time of day, day of the week, day of the month, or some combination of these. This is ideal for making sure your phone will not ring in the middle of the night.
A rule may contain only some of these limitations (e.g., time), in which case the others will contain a wildcard (e.g., calls from any phone number, or made to any of your DID numbers).
Each rule provides instructions about exactly how a call should be processed. It contains a sequence of one or more of the following actions:
- Reject – simply drop the call without answering it.
- Ring – ring on the current IP phone.
- Forward – redirect to the numbers defined in the call forward/follow-me settings.
- Voicemail – connect the call to this phone’s voice mailbox.
When assigning an action to a rule, you will be offered a list containing all the possible combinations based on the currently available features for this account. For instance, the Forward option will be present only if the call forwarding service is currently enabled for the account.
Call screening algorithm
When a new call arrives to PortaSwitch, call information is sequentially checked against all defined call screening rules. The call information (ANI, DNIS, and current time) is checked against each rule’s limitations. If at least one of these does not match, the rule is skipped and processing moves on to the next one. If there is a match for all three limitations, then the rule’s actions are executed and no further rules are processed. If none of the rules matches (or if no call processing rules have been defined), then the default rule is applied, as follows:
- Ring on the IP phone.
- If not answered within a certain time (defined by the Timeout parameter in Service Features for the Voice Calls service), and if the account has call forwarding enabled, attempt to connect the call to the phone numbers listed there.
- If the call is still not answered and the account has the UM service enabled, forward the call to voicemail; otherwise drop the call.