Table of Contents


CLI/ANI is the From part of the SIP INVITE message, which contains information about the caller. Specifically, it is the name and number of the person attempting to contact a user in a VoIP system, more commonly known as caller ID in standard phone systems.

CLI options are set in Customer > [customer] > Routing > CLI.


Whitelisted CLIs are those that allowed to pass through the system. Add the CLI number into the designated box and it will be cleared.

Force CLI

To change the CLI that is presented for another, enter the CLI you wish to present, and click the Force CLI box. It will allow you to override the previous number with one that is accepted. You can add a whitelist of CLIs and select Force on a CLI which you wish to be used if none of the others in the whitelist match.

CLI Restrict

CLI Restrict lets you block calls. The blocked CLI is added in the provider rate card:

  1. Click Management > Rate Card.
  2. Select Provider Rate Card > Edit > Advanced.
  3. Enter the CLI/ANIs you want to block.
  4. Click Save.

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Replace Specific CLI

A CLI can be re-written. For example, you can add 123456789 in the CLI box, and then rewrite by adding 987654321 in the re-write CLI box.


P-Asserted-Identification is another SIP Header. It is not presented, but allows telephone companies to identify originators on a network-only level. A P-Asserted-ID uses the same syntax as Replace CLI.

Advanced CLI Match & Manipulation

The CLI system uses Regular Expressions to match and replace numbers. Here are a few examples:

CLI Replace CLI Description
123456789 ^1234 Allows only numbers starting with 1234 to pass
123456789 789$ Allows only numbers ending with 789 to pass
12345678912 ^[0-9]{11,12}$ Allows only numbers with 11 or 12 digits to pass
+123456789 ^+([0-9]+)$ \1 Remove leading +
01782123456 ^0([1-9]+)$ 44\1 Remove leading 0 and replace with 44

To learn more about writing regular expressions, visit There are lots of tutorials and excercises available for all levels of expertise.