Category: Kamailio

Kamailio DNS and NAT

DNS sub-system in Kamailio DNS failoverDNS load balancingNAT ( Network Address Translation)NAT ( Network Address Translation)Why is NAT is important in SIP?Types of NAT solutionsNAT behavioursRTP NATFixing NATNAT Traversal ModuleWhy use keepalive when Registrations are already there for NATing ?How keepalives work for NATing ?function nat_keepalive()ParamsFunctionsclient_nat_test()fix_contact()nat_keepalive()Pseudo VariablesStatisticsNATHelper ModuleNAT pinging typesUDP packetSIP requestparamsfunctionsPseudo VariablesRPC Commands In … Continue reading Kamailio DNS and NAT

Kamailio WebRTC SIP Server

Why Kamailio?Kamailio SIP Signaling ProxySystem ArchitectureTLS module Configuration GuideStep 1: Create Certificate Directory StructureStep 2: Generate Certificate Authority (CA)Step 3: Generate Server CertificateStep 4: Install CertificatesStep 5: Create CA Certificate ListStep 6: Configure TLS in kamailio.cfgTesting TLS ConfigurationWebsocket moduleConfigurationNAT Detection and HandlingRTPengineInstallationRunning RTP EngineKamailio RTP Engine IntegrationTesting RTP EngineJSSIPJSSIP WebRTC client for KamailioSIP over WEBSOCKET … Continue reading Kamailio WebRTC SIP Server

Lua Scripts for kamailio Routing

Kamailio uses a native scripting laguage for its configuration file kamailio.cfg . This components of this file are : global parameters loading modules module parameters routing blocks like request_route {…}, reply_route {…}, branch_route {…} etc These parameters including initialization event routes , are interpeted and loaded at kamailio startup. We know that restart of sip … Continue reading Lua Scripts for kamailio Routing

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 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 transcoding, topology concealment and load balancing is also achievable via a SBC such as 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 and even had NAT and anti DOS attack support .

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 … Continue reading Proxying Media Streams via Kamailio’s RTP Proxy

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 … Continue reading Kamailio Call routing and Control

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