carriers-sip
IP authentication
A way for your carrier to recognize your dialer by its public IP address instead of a username and password, so calls connect without login credentials.
IP authentication is one of two common ways your carrier decides whether to accept calls from your dialer. Instead of checking a username and password, the carrier keeps a list of approved public IP addresses. When a call arrives from an address on that list, it goes through. If the address is not on the list, the call is rejected. This is the simpler of the two methods because your SIP (Session Initiation Protocol) server does not have to log in at all.
The alternative is credential-based login, where your dialer sends a Registration string with a username and secret to prove who it is. Both methods are valid, and many carriers let you pick. IP authentication works well for a server that has a fixed public address, which most hosted VICIdial boxes do. You give the Carrier your IP, they add it to your account, and the SIP trunk starts passing calls.
When IP authentication is the better choice
Reach for IP authentication when your server has a stable address that will not change. It avoids storing a password on the box and it sidesteps registration timeouts, since there is no login session to keep alive. The downside is that if your IP ever changes, calls stop until the carrier updates their list. If you do not control your address, credential login is the safer bet.
On the dialer side, an IP-authenticated SIP peer is configured without a secret, and the carrier's address is set as the host. If you are deciding between methods or picking a provider, the trade-offs in choosing a SIP carrier are worth a read. Whichever you use, the goal is the same: a Trunk that authenticates cleanly and stays up.
Related terms
Carrier
A carrier is the phone company that actually carries your calls onto the public phone network — VICIdial dials, the carrier delivers.
Registration string
The line of settings — username, password, and server address — that tells your SIP device or trunk how to log in and announce itself to a provider.
SIP (Session Initiation Protocol)
The standard signaling protocol that sets up, manages, and ends internet phone calls — how VICIdial talks to phones and carriers.
SIP peer
A SIP peer is any single phone or trunk the server knows how to talk to, with its own name, credentials, and connection settings.
SIP trunk
A virtual phone line over the internet that connects your dialer to a carrier, letting you place and receive many calls at once without physical wires.