carriers-sip
E.164
E.164 is the international standard for writing phone numbers with a plus sign, country code, and subscriber number, giving every number one clear global format.
E.164 is the international standard for how a phone number should be written so that any network anywhere can understand it. The format is a plus sign, the country code, and then the national number, with no spaces or dashes. A United States number like 415 555 0142 becomes +14155550142. The whole number stays under fifteen digits, which is the maximum the standard allows.
This matters because phone numbers are written a hundred different ways by humans, and machines need one form they can trust. When your dialer hands a call to a SIP (Session Initiation Protocol) provider, sending the destination in E.164 removes guesswork about country and area codes. Many a Carrier will reject or misroute numbers that are not in this format, especially for international traffic.
In a VICIdial setup, E.164 shows up in a few places. Your owned DID (direct inward dialing) numbers and any Toll-free number lines are easiest to manage when stored in this single canonical form. The source number you present, the ANI, and the number you dial, the DNIS, both travel cleaner when formatted to the standard rather than left in a local style.
A practical tip: decide early whether your lead lists store numbers in E.164 or in a local format, then convert at one clear point rather than sprinkling fixes everywhere. Mixing formats is a frequent cause of calls that simply fail to connect because the carrier could not figure out where the digits were supposed to go.
Related terms
ANI
ANI, short for Automatic Number Identification, is the phone number your call carries as its source, which the person you dialed usually sees as caller ID.
Carrier
A carrier is the phone company that actually carries your calls onto the public phone network — VICIdial dials, the carrier delivers.
DID (direct inward dialing)
A DID (direct inward dialing) is a phone number you own that routes incoming calls straight into VICIdial, usually to a chosen inbound group.
DNIS
DNIS (dialed number identification service) tells VICIdial which of your numbers an incoming caller dialed, so the same server can route different lines differently.
SIP (Session Initiation Protocol)
The standard signaling protocol that sets up, manages, and ends internet phone calls — how VICIdial talks to phones and carriers.
Toll-free number
A toll-free number is a phone number, often starting 800 or 888, where the business pays for the call instead of the person dialing in.