Achieving service redundancy in two steps with unified clustering in OpenSIPS 3.0

A hot backup means redundancy, redundancy means more uptime, more uptime means a better SLA, a better SLA means happier customers and more money. Building redundancy is a must when moving your service into production. And a typical approach for achieving redundancy is by implementing an active - backup setup with full realtime synchronization between … Continue reading Achieving service redundancy in two steps with unified clustering in OpenSIPS 3.0

Gateway between SIP and SMPP messages

While the SIP protocol is one of the most popular protocols used for voice calls, the SMPP (Short Message Peer-to-Peer) is one of the most widely used protocols for sending text messages. Having both of them offered by your service enhances your platform with more compatibility and flexibility. In order for your customers to have … Continue reading Gateway between SIP and SMPP messages

SIP bridging over multiple interfaces

There are scenarios where you need OpenSIPS to route SIP traffic across more than one IP interface. Such a typical scenario is where OpenSIPS is required to perform bridging. The bridging may be between different IP networks (like public versus private, IPv4 versus IPv6) or between different transport protocols for SIP (like UDP versus TCP … Continue reading SIP bridging over multiple interfaces

Handling SIP Redirect Requests in realtime

The SIP redirect mechanism is a simple and straight forward one  - the originally contacted destination indicates, via a 3xx reply, that a different set of destinations should be contacted. The SIP redirect is mainly used for calls (for INVITE requests), even if the RFC3261 does not limit it to that. Usage cases The primary … Continue reading Handling SIP Redirect Requests in realtime

Troubleshooting missing ACK in SIP

We all experienced calls getting self disconnected after 5-10 seconds - usually disconnected by the callee side via a BYE request - but a BYE which was not triggered by the party behind the phone, but by the SIP stack/layer itself. This is one of the most common issues we get in SIP and one … Continue reading Troubleshooting missing ACK in SIP

SIP-I and SIP with OpenSIPS 2.3

SIP-I considerations The SS7 interconnections are always painful. Both as cost and technical difficulty/complexity. So, as a more accessible alternative, the carriers started to offer SIP interconnection via SIP-I (SIP Infrastructure). SIP-I  or SIP Infrastructure (define by ITU) is very similar to SIP-T or SIP for Telephones (defined by IEFT). SIP-I is very powerful when … Continue reading SIP-I and SIP with OpenSIPS 2.3

Migrating registrations to OpenSIPS 2.2

Starting with OpenSIPS 2.2 the registered SIP contacts (stored the location table) have a new unique ID named contact ID. This new ID is contact specific (computed based on various contact elements) and it replaces the old opaque ID which was a simple DB auto-increment key. But why ? to increase the efficiency of the DB operations, by using a single value … Continue reading Migrating registrations to OpenSIPS 2.2

Mid-registrar: scalable registration and call forking

The new mid-registrar functionality is now available with OpenSIPS 2.3 (current development branch) ! What is a mid-registrar ? The mid-registrar is a mid-component of a SIP platform, designed to work between end users and the platform's main registration component. It opens up new possibilities for leveraging existing infrastructure in order to continue to grow (as … Continue reading Mid-registrar: scalable registration and call forking

How To Proxy SIP Registrations

SIP registration is the process through which SIP user devices (desk phones, soft phones, etc.) periodically announce or refresh their network location to a SIP registrar, for an upcoming period of time. Once registered with the VoIP platform, the device is able to receive calls or messages from other devices. Proxying SIP registrations In some cases, we may want … Continue reading How To Proxy SIP Registrations