OpenSIPS Examples

Working opensips.cfg files for the roles an OpenSIPS server can take: registrar, stateless and stateful proxy, load balancer, session border controller and media relay. Each example is self contained and can be read on its own.

Start with a minimal config Browse the repository

OpenSIPS is a “multi-functional, multi-purpose signaling SIP server used by carriers, telecoms or ITSPs”. Its routing logic is split across route blocks that fire at different points in a transaction, so most of these examples are organised around which block does the work.

Getting started

The smallest configurations that still answer SIP traffic.

Minimal configuration The fewest modules and route lines needed for OpenSIPS to start and reply. Stateless proxy Forwarding requests without keeping transaction state.

Route types

OpenSIPS splits its logic across route blocks that fire at different points in a transaction.

Branch route Per-branch handling inside t_relay(), used for parallel and serial forking. Failure route Reacting to negative replies and retrying towards another destination. Reply route Inspecting and rewriting responses on their way back. Local route Triggered for requests OpenSIPS generates itself rather than relays. Record route Staying in the path of sequential in-dialog requests. Inbound and outbound flows Separating incoming from outgoing call legs across TCP and UDP.

Registration and users

Location storage and per-user services.

Registrar Handling REGISTER and persisting contacts in user location. Speed dial Mapping short numbers to full SIP URIs.

Proxying and scaling

Distributing traffic and sitting at the border of the network.

Load balancer Spreading calls across a pool of destinations by load. Session border controller Paired inbound and outbound SBC configurations with an address table. Proxy with accounting A full proxy configuration on 2.2.7 with CDR accounting.

Media

Relaying RTP between endpoints.

RTPProxy Media relay and SDP rewriting through RTPProxy.

Security and traffic control

Deciding who may call, how often, and spotting abuse.

Permission control Allowing or denying requests from known address groups. Fraud detection Watching call patterns for fraudulent behaviour. Rate limiting over REST Deferring per-account call rate decisions to an external API with rest_client.

Data stores

Caching and persisting state outside the process.

Redis cache Using cachedb_redis for shared, in-memory state.

Notes

Reference material that applies across the examples.

Installation Installing OpenSIPS from packages or source, and running menuconfig.

The route blocks

Block	Fires when
`route`	A SIP request arrives and needs a routing decision.
`branch_route`	Each outgoing branch leaves, from inside `t_relay()`.
`failure_route`	A negative final reply comes back and the transaction can be retried.
`onreply_route`	A reply passes through on its way to the caller.
`local_route`	OpenSIPS itself generates a request rather than relaying one.
`error_route`	A parsing or script error occurs.
`startup_route`	The server starts, before any traffic is accepted.
`timer_route`	A configured interval elapses.
`event_route`	A module raises an event.

Running an example

git clone https://github.com/altanai/opensipsexamples.git
cd opensipsexamples/<example>

# check the configuration; returns 0 when it is valid
opensips -C opensips.cfg

# run in the foreground with logging to stderr
opensips -f opensips.cfg -E -D

Set listen, mpath and any database URLs to match your host first. Module and core versions must agree, otherwise OpenSIPS refuses to load the module with a version_control error — see the installation notes. Every change to the configuration needs a restart.