SIP Express Router (SER) is a high-performance, configurable, free SIP server licensed under the open-source GNU license . It can act as SIP (RFC 3261) registrar, proxy or redirect server.
OpenSER is a mature and flexible open source SIP server (RFC3261). It can be used on systems with limitted resources as well as on carrier grade servers, scaling to up to thousands call setups per second. It is written in pure C for Unix/Linux-like systems with architecture specific optimizations to offer high performances. It is customizable, being able to feature as fast load balancer; SIP server flavours: registrar, location server, proxy server, redirect server; gateway to SMS/XMPP; or advanced VoIP application server.
CDRTool provides mediation, accounting and tracing for Call Detail Records generated by OpenSER by using RADIUS protocol and OpenSER siptrace facility. CDRTool is a simple to use WEB application, which can be put in service with minimal training of the helpdesk and operations staff. It gives you or your customers instant access to SIP usage information, traces from CDR level to protocol level, statistics grouped by criteria like release cause, destination or billing parties and can help pin-point SIP/ISDN call flows and failure reason.
WeSIP - The OpenSER converged Application Server
WeSIP is a SIP and HTTP Converged Application Server built on top of OpenSER !!!
WeSIP adds a J2EE layer to OpenSER so you can benefit from the existing OpenSER modules and features, which already implement nice functionality like registrar,nat traversal, diameter authentication or radius accounting at blazing speeds,while at the same time enjoying the ability to develop and deploy new converged SIP and HTTP applications in an J2EE environment.
Another links
PrimiSIP v070531-aa78, a stateless SIP server in Perl
Performance Results for OpenSER and SIP Express Router
INRIA - SIP.edu deployment notes
Example of a VoIP deployment using opensource and commercial products (from endeavor-technologies.com)
OpenSER VS SER <p> </p>
