Author: altanai

Specialized in CPaaS, carrier-grade WebRTC-SIP telecom platforms for Unified communication-collaboration, signaling gateways, SBC, soft turrets, IoT-surveillance and telecom integrations. Ardent contributor to Open Source software, avid freelancer, innovator and technical writer (telecom.altanai.com ). Inventor of "RamuDroid" an IOT Road-Cleaning robot Author of book "WebRTC Integrator's Guide" published by Packt

Asterisk – installation and dial plans for WebRTC supported PJSIP clients

Asterisk is a framework or toolkit designed for VOIP systems . It can support Enterprise communication systems like PBXs, call distributors, VoIP gateways , conference bridges etc . It is open source and free to use . It is developed in C and runs in linux . Technically , Asterisk has protocol support for many … Continue reading Asterisk – installation and dial plans for WebRTC supported PJSIP clients

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 Modules

If you are new are opensips you cab read Over view of Opensisp SIP server here https://telecom.altanai.com/2018/06/06/opensips/ This article talks about modules and subparts of Opensips and their role in defining the purpose and application of Opensips which can be as an lighweight proxy to loadbalancer or even as AAA server. Dispatcher Module This modules … Continue reading Opensips Modules

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.

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) framework. Post v5 of Kamailio , the interpreters of these languages were integrated with Kamailio and feature rich SIP routing logic could be written with them for runtime execution. The routing blocks are in form of functions written in a KEMI supported scripting language such as Lua as discussed in this article. Other components are still initialized by kamailio.cfg at startup. Apart from above mentioned advantages of programming languages , another plus point is that it enables test-cases , debug functionality without having to restart the server for code update.

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.

Secure Communication with SRTP and key managemnt protocols like SDES, ZRTP and DTLS

With advent of Voice over IP, the real time streaming of data/audio/video also became critically important to be protected from eavesdropping or modification over the open internet. While Secure Real-time Transport Protocol (SRTP) is a profile of the Real-time Transport Protocol (RTP), which can provide confidentiality, message authentication, and replay protection to the RTP traffic and to the control traffic for RTP, the Real-time Transport Control Protocol (RTCP).

Opensips as SIP gateway

Load BalancerHealth Monitoring OpenSIPS config fileSubscriber and Location OpenSIP provided dispatcher modules which computes hashes over parts of the request and selects an address from a destination set which is then as outbound proxy. Combination of opensips working scenarios scripts with code is at https://github.com/altanai/opensipsexamples. In the config of opensips load the file dispatcher.list with … Continue reading Opensips as SIP gateway

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 .

Connected Self Driving Cars

Self driving tech includes Radar, Ultrasonic, Passive video, LIDAR (Light Detection and Radar) , IoT , sensors , advanced GPS so on . Machine learning models on Computer vision is disrupting automobile industry and likely to create a multi billion dollar market in near future.. To make the traffic and transportation infrastructure more robust, "connected … Continue reading Connected Self Driving Cars

Automatic Garbage Segregation by Machine Learning

Sharing work in progress on the automatic garbage segregation system. This operates as an independent unit in addition to Ramudorid ( a road cleaning robot). The system deals with incorporating image and edge detection algorithm over incoming video media to classify and identify items into one of the following categories Recyclable waste - paper , … Continue reading Automatic Garbage Segregation by Machine Learning

Blockchain integarted with Voice over IP platforms

Market analysts and industry specialist have said that block-chain is a revolutionizing technology which will create a decentralized network for not just currency exchange but also many other aspects such as double spent problem , universal identities , document management etc . Example : Bitcoin protocol , which contains a full record of every transaction ever executed with the currency at any time in past. It is also a solution to problem like black - money , double spending , tax evasions etc. Other areas include: