Kamailio DNS and NAT
DNS sub-system in Kamailio DNS failover DNS load balancing NAT ( Network Address Translation) NAT ( Network Address Translation) Why is NAT is important in SIP? Types of NAT solutions NAT behaviours RTP NAT Fixing NAT NAT Traversal Module Why use keepalive when Registrations are already there for NATing ? How keepalives work for NATing…
Kamailio WebRTC SIP Server
Kamailio is an open-source SIP (Session Initiation Protocol) server that provides advanced routing, protocol support, and media handling capabilities. This article demonstrates how to configure Kamailio with RTP Engine to enable WebRTC-to-SIP interoperability, allowing web-based real-time communication clients to seamlessly connect with traditional SIP User Agents (UAs). The purpose of this article is to demo the process…
Lua Scripts for kamailio Routing
We know that restart of sip server hinders all ongoing traffic and slows development of routing logic. Due to limitation of customization with native language and mostly due to the fact that interpreter pre-compiles kamailio.cfg at startup preventing routing script to reload without restart, other programming languages were used such as Kamailio Embedded Interface (KEMI)…
RTPengine on kamailio SIP server
RTPengine is a proxy for RTP traffic and other UDP based media traffic over either IPv4 or IPv6. It can even bridge between diff IP networks and interfaces . It can do TOS/QoS field setting. It is Multi-threaded , can advertise different addresses for operation behind NAT.
Kamailio Security
Kamailio security modules , Sanity , permission , topos , ACL , Fireqall , anti flood,s ecfilter module
Kamailio as Inbound/Outbound proxy or Session Border Controller (SBC)
role of an SBC is to shield the core network from external entities such as user agent’s , carrier network while also providing security , auth and accounting services . In many cases SBC also provides NAT traversal and policy control features ( such as rate limiting , ACL etc ) . In advanced cases…
Kamailio Architecture, Core and Modules
kamailio has a modular architecture with core components and modules to extend the functionality, this article will be discussing few of the essential modules in Kamailio.
Telephony Solutions with Kamailio
Rich features set suiting to telephony domain that includes IMS extensions for VoLTE; ENUM; DID and least cost routing; load balancing; routing fail-over; Json and XMLRPC control interface, SNMP monitoring. To integrate with a carrier grade telecom network as SBC / gateway / inbound/outbound proxy , it can act as IPv4-IPv6 gateway , UDP/TCP/SCTP/WS translator…
Proxying Media Streams via Kamailio’s RTP Proxy
Kamailio is a SIP server which does not play any role by itself in media transmission path. this behaviour leads to media packets having to attempt to stream peer to peer between caller and callee which in turn many a times causes them to get dropped in absence of NAT management To ensure that media…
Kamailio Call routing and Control
Kamailio SIP server evolved from SER and OpenSER. Written in ANSI C , primarily it is an open source proxy SIP server. RFC 3261 compliant and has support for various Operating system to install and run on as alpine , centos , deb , fedora , freebsd , netbsd , obs , openbsd , opensuse…
Kamailio Transaction management and Transaction Module tm
Kamailio is basically only a transaction stateful proxy, without any dialog support build in. Here the TM module enables stateful processing of SIP transactions. State is a requirement for many complex logic such as accounting, forking , DNS resolution
Telecom R & D 