Any Other Carrier
SessionPBX works with any carrier that provides a standard SIP trunk. The guides in this section cover carriers we have templates for; everything else uses a generic template and the same steps.
Choose a template
On the Provider step, pick the entry that matches how your carrier authenticates:
- Generic carrier (IP authentication) — the carrier recognises your address and issues no SIP password.
- Generic carrier (username and password) — the carrier challenges calls with a password but does not ask you to register.
- Generic carrier (registration) — the carrier expects the phone system to register to it. See Registration-based Carriers.
Choosing Other / not listed leaves every field blank, which is fine if you have the carrier’s settings to hand.
A generic template fills in the settings that are the same everywhere — port, transport, direction — and leaves everything specific to your account blank. A blank field is deliberate: a prefilled value that is wrong is harder to spot than an empty one.
Information to obtain from your carrier
- Carrier or proxy hostname, port and transport
- Whether the trunk uses source-IP authentication, a password, or registration
- Authentication username, password and realm where they apply
- From-domain, if it differs from the carrier host
- The carrier’s signalling IP addresses or CIDR ranges
- Your inbound numbers and an authorised outbound caller ID
- Whether the carrier requires the calling number in P-Asserted-Identity
Ask the carrier to confirm how it expects numbers to be formatted, and which SessionPBX regional service address it should send calls to.
Settings worth asking about
Caller ID assertion. Some carriers screen your outbound caller ID and read it from P-Asserted-Identity rather than From. Set Assert caller ID in on the Outbound step if the carrier asks for it. From is always sent regardless.
More than one gateway. If the carrier gave you several hosts for resiliency, add the extras under Additional gateways. Calls try them in order of priority, and share between gateways at the same priority.
Refusing unknown numbers. Turn on Refuse unknown numbers so calls for numbers not listed on the trunk are rejected rather than passed on. Leave it off if the carrier sends numbers you have not listed.
What is not supported
Some settings that other phone systems expose per trunk are not configurable here:
- codec selection per trunk — codecs are set for the whole system
- a separate outbound proxy from the carrier host
- SRV or NAPTR lookup of the carrier host
- per-trunk TLS certificates, certificate authorities or SNI
- identifying inbound calls by anything other than the dialled number
If your carrier requires one of these, contact support before ordering the service.