How to set up a SIP proxy with NkSIP?

Start by cloning the repository, running 'make' and 'make tests', then use the included callback module to define a service with SIP listeners. Refer to the nksip_samples repository for tutorials on implementing proxy logic with serial or parallel forking.

NkSIP vs Kamailio for building a SIP server?

NkSIP is Erlang-based, offering hot upgrades and built-in scalability via Erlang's concurrency, ideal for custom, high-availability applications. Kamailio is C-based, often preferred for raw performance and extensive pre-built modules, but lacks native hot code upgrades. Choose based on language preference and deployment flexibility.

Does NkSIP support SIP over WebSockets?

Yes, NkSIP supports WebSocket transports (WS and WSS) as part of its multi-transport capabilities, enabling SIP communication in web and real-time applications. This is listed in the features for handling thousands of simultaneous sessions.

What performance benchmarks does NkSIP have?

NkSIP achieves over 3,000 call cycles (INVITE-ACK-BYE) or 10,000 registrations per second on common hardware like a 4-core i7 MacMini, as stated in the README. It scales automatically using all available processor cores for high throughput.

How to add custom authentication in NkSIP?

Use the standard Digest Authentication plugin or create a custom plugin via the extensible architecture. Implement callback functions in your service module to handle authentication logic, with details provided in the plugin documentation.

Is NkSIP suitable for client-side SIP applications?

NkSIP is primarily designed for server-side applications like proxies and registrars. While it can act as a UAC for outgoing requests, it lacks built-in GUI or end-user client features, making it less ideal for consumer-facing SIP clients.

NkSIP — Erlang SIP Application Server

What is NkSIP?

NkSIP is an Erlang SIP application server framework that facilitates building server-side SIP applications such as proxies, registrars, and B2BUAs. It abstracts SIP complexity while allowing full control over requests and responses, enabling developers to create scalable and robust telephony solutions. The framework supports multiple transports and includes a plugin system for extensibility.

Target Audience

Erlang developers and engineers building SIP-based telephony infrastructure, including proxies, session border controllers, and real-time communication servers.

Value Proposition

Developers choose NkSIP for its Erlang-based concurrency and fault tolerance, which ensure high scalability and reliability. Its plugin mechanism and hot upgrade capabilities allow for flexible, maintainable deployments without downtime.

Erlang SIP application server

Use Cases

Best For

Building SIP proxy servers with serial or parallel forking
Developing Session Border Controllers (SBCs) for VoIP networks
Creating registrar servers for SIP user registration
Implementing Back-to-Back User Agents (B2BUAs) for call control
Generating SIP load for testing and performance benchmarking
Developing scalable SIP application servers with hot code upgrades

Not Ideal For

Teams not using Erlang or unfamiliar with Erlang/OTP concurrency models
Projects needing a pre-built, out-of-the-box SIP server with minimal configuration
Applications requiring extensive graphical user interfaces or web-based management tools
Small-scale, static deployments where hot upgrades and high scalability add unnecessary complexity

Pros & Cons

Pros

Full SIP Method Support

Implements all SIP methods like INVITE, REGISTER, and OPTIONS as UAC, UAS, or Proxy, enabling versatile server applications such as proxies and B2BUAs.

Multi-Transport Scalability

Supports UDP, TCP, TLS, SCTP, WS, and WSS transports, handling thousands of simultaneous sessions and automatically utilizing all processor cores for high performance, as noted with 3,000+ call cycles per second.

Extensible Plugin Architecture

Features a low-overhead plugin mechanism for adding functionality like authentication and event handling without modifying the core, reducing development overhead.

Hot Code Upgrades

Allows on-the-fly configuration, code upgrades, and behavior changes without downtime, leveraging Erlang's runtime for zero-duration maintenance.

Cons

Erlang Expertise Required

Demands proficiency in Erlang and OTP, which has a steeper learning curve compared to more common languages, limiting accessibility for non-Erlang developers.

Testing Instability

The README admits that Travis CI fails sometimes due to timers, indicating potential reliability issues in continuous integration and testing environments.

Limited Out-of-the-Box Features

Core functionality requires implementing callback modules or using plugins, which can be complex for simple use cases, despite sane defaults.

What is NkSIP?

Target Audience

Erlang developers and engineers building SIP-based telephony infrastructure, including proxies, session border controllers, and real-time communication servers.

Value Proposition

Use Cases

Best For

Building SIP proxy servers with serial or parallel forking
Developing Session Border Controllers (SBCs) for VoIP networks
Creating registrar servers for SIP user registration
Implementing Back-to-Back User Agents (B2BUAs) for call control
Generating SIP load for testing and performance benchmarking
Developing scalable SIP application servers with hot code upgrades

Not Ideal For

Teams not using Erlang or unfamiliar with Erlang/OTP concurrency models
Projects needing a pre-built, out-of-the-box SIP server with minimal configuration
Applications requiring extensive graphical user interfaces or web-based management tools
Small-scale, static deployments where hot upgrades and high scalability add unnecessary complexity

Pros & Cons

Pros

Full SIP Method Support

Implements all SIP methods like INVITE, REGISTER, and OPTIONS as UAC, UAS, or Proxy, enabling versatile server applications such as proxies and B2BUAs.

Multi-Transport Scalability

Extensible Plugin Architecture

Features a low-overhead plugin mechanism for adding functionality like authentication and event handling without modifying the core, reducing development overhead.

Hot Code Upgrades

Allows on-the-fly configuration, code upgrades, and behavior changes without downtime, leveraging Erlang's runtime for zero-duration maintenance.

Cons

Erlang Expertise Required

Demands proficiency in Erlang and OTP, which has a steeper learning curve compared to more common languages, limiting accessibility for non-Erlang developers.

Testing Instability

The README admits that Travis CI fails sometimes due to timers, indicating potential reliability issues in continuous integration and testing environments.

Limited Out-of-the-Box Features

Core functionality requires implementing callback modules or using plugins, which can be complex for simple use cases, despite sane defaults.

NkSIP

What is NkSIP?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

NkSIP

What is NkSIP?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?