Number lists#

An inbound Number List filters calls by the caller’s number (CLI). Assign a Number List to an inbound SIP trunk or PSTN trunk to allow or reject calls from specific numbers or prefixes before they reach your destination.

Each Number List has a Mode that defines how its items are matched, a set of items with their own Action, and a Default Action for callers that no item matches. Create and manage Number Lists under Voice > Inbound Trunks > Number Lists.

How number lists work#

When a call arrives on a trunk with an assigned Number List, DIDWW compares the caller’s number with the list items according to the list’s Mode:

Full number match matches only an item identical to the complete calling number.
Prefix match matches an item whose digits appear at the beginning of the calling number, provided the complete calling number meets the item’s Min. Length and Max. Length limits.

If an item matches, its Action allows or rejects the call. If no item matches, the list’s Default Action applies.

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flowchart LR

    caller["Caller"] --> |dials DID| trunk["SIP or PSTN trunk"]
    trunk --> list{"Item matches<br>caller's number?"}
    list --> |yes| item["Item Action"]
    list --> |no| default["Default Action"]
    item --> result["Call allowed or rejected"]
    default --> result

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    classDef process fill:#ccfbf1,stroke:#2dd4bf,color:#1f2d3d,stroke-width:1.5px

    class caller,result endpoint
    class trunk,list,item,default process

    linkStyle default stroke:#0066cc,stroke-width:1.5px

Allow and block lists#

Combine the Default Action with item actions to build either a blocklist or an allowlist.

Objective	Configuration	Behavior
Block specific callers	Set Default Action to Allow call and add items with Reject call.	DIDWW rejects calls from the listed numbers or prefixes and allows all other calls.
Allow only specific callers	Set Default Action to Reject call and add items with Allow call.	DIDWW allows calls from the listed numbers or prefixes and rejects all other calls.

Number lists and trunks#

Assign a Number List in the trunk’s CLI Number List field on the Number Translations tab. Each trunk can use one Number List, and the same list can be assigned to multiple trunks.

For a SIP trunk, the list is matched against the caller’s number after the trunk’s CLI Format and CLI Prefix are applied. If you change those settings, update the list items to the new format.
For a PSTN trunk, the list is matched against the caller’s number presented to the PSTN destination.

A Number List that is assigned to a trunk cannot be deleted. To find the trunks that use a list, filter the Trunks tab by CLI Number List.