Tag: Sip

SIP Trunks

Traditional trunk call SIP trunk (older) systems Centralized SIP Trunk Model SIP trunking is an IP-based alternative to ISDN trunking services Planning to set up SIP trunk Features of SIP trunking Future of SIP trunks With the dawn of IP telephony service and cloud communication platforms in recent years, the SIP has caught the attention … Continue reading SIP Trunks

Hosted IP-PBX and SBC

SBC ( Session Borde Controllers ) are basically gateways that provide interconnectivity between the hosted IP-PBX of the enterprise to the outside world endpoints such as telco service provider, PSTN/ TDM , SIP trunking providers or even third party OTT provider apps like skype for business etc.

RTCP Reports and QoE metric calculation

RTCP works alongside RTP to monitor and control media streams with QoS feedback, synchronization and session management . This writeup describes the key format and functions of this protocol RTCP (Real-Time Transport Control Protocol ) RTCP Control and ManagementGathers statistics on media connectionSR: Sender Report RTCP PacketRR: Receiver Report RTCP PacketSDES: Source Description RTCP PacketBYE: … Continue reading RTCP Reports and QoE metric calculation

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

Opensips

Due to its very flexible and customisable routing engine it can be used in number of scenarios such as an SIP proxy or a router and due to its high throughput it is widely recommended as an enterprise grade inbound/outbound proxy server.

VOIP Call Metric Monitoring and MOS ( Mean Opinion Score)

Metrics for monitoring a VOIP call can be obtained from any node in media path of the call flow . Essentially used for analysis via calculation and aggregation , and sometimes used for realtime performance tracking and rectification too . Rating Factor (R-Factor) and Mean Opinion Score (MOS) are two commonly-used measurements of overall VoIP call quality. R-Factor: A value derived from metrics such as latency, jitter, and packet loss per ITU‑T Recommendation G.107. It assess the quality-of-experience for VoIP calls on your network. Typical scores range from 50 (bad) to 90 (excellent).

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 .

Freeswitch PBX system

IP PBXFreeSWITCHClass 4 switchClass 5 switchfreeswitch-setup-as-hosted-ip-pbxFreeswitch as B2BUA This article talks about setting up an in-house hosted Enterprise PBX system for sure and private communication within enterprise communication. IP PBX A PBX acts as the central switching system for phone calls within a business. Cloud Hosted IP PBX SystemsOn-premise IP PBX An IP PBX is … Continue reading Freeswitch PBX system

Session Border Controller (SBC) for WebRTC

SBC became important part of comm systems developed over SIP and MGCP. SBC offer B2BUA ( Back to Back user agent) behavior to control both signalling and media traffic.

IPTV ( Internet Based Television ) and VOD ( Video on Demand)

IPTVIPTV multicast Mobile TV Video On Demand (VoD)WebRTC for IPTV and VOD We know the power of the Internet protocol suite as it takes on the world of telecom. Already half of the Communication has been transferred from legacy telecom signaling protocols like SS7 to IP based communication ( Skype, Hangouts, WhatsApp, Facebook Messenger, Slack, … Continue reading IPTV ( Internet Based Television ) and VOD ( Video on Demand)

BEA Weblogic SIP server

Bea server is a old SIP servlet container ie application server which is used to embed control logic in a program. 1. Install Bea Weblogic 2. Follow the Installation steps Make domain 3. Goto the installation directory . Usually C:/bea/user_projects/mydomain/ . click on startweblogic.cmd in windows. In case the system is linux run startweblogic.sh script … Continue reading BEA Weblogic SIP server

Legacy Telecom Networks

Characteristics of Legacy Systems PSTN (Public Switched Network) TDM ISDN (Integrated Service Digital Network) Services of Legacy Telecom Networks I use the term legacy telecom system many a times , but have not really described what a legacy system actually is . In my conferences too I am asked to just exactly define a legacy … Continue reading Legacy Telecom Networks