Igor Delac, VoIP Developer in Zagreb, Croatia
Igor Delac

VoIP Developer in Zagreb, Croatia

Member since April 9, 2014
Igor is an enthusiastic and skilled technology professional with experience in Java development, system administration, and more. He loves to experiment and work with new technologies, and has proven ability to learn whatever is necessary to solve a problem at hand.
Igor is now available for hire



  • Linux 10 years
  • VoIP 9 years
  • Java 7 years
  • SQL 4 years
  • Spring LDAP 4 years
  • Vaadin 3 years
  • LDAP 3 years
  • Spring 5 2 years


Zagreb, Croatia



Preferred Environment

Eclipse, NetBeans

The most amazing...

...thing I've coded is a fast response to ldap request with precoded answers.


  • Java Developer

    2017 - PRESENT
    SedamIT d.o.o.
    • Developed a lawful interception system for monitoring telecom network traffic.
    • Created an RMS system for active VoIP call recording.
    Technologies: Spring, Maven, Eclipse, Git
  • Java Developer

    2013 - 2015
    Ericsson Nikola Tesla
    • Tested and coded a provisional gateway for HLR.
    • Created support for LDAP by implementing openLDAP and custom Java LDAP servers.
    • Built a high-performance LDAP server.
    • Developed support for Linux tools.
    • Optimized the TCP stack on Linux 2.6 and 3.0 kernel series.
    Technologies: Java, Eclipse, Git, Linux
  • Software Tester

    2011 - 2012
    Ericsson San Jose
    • Installed the Entrisphere/Ericsson BLM1500 multiplexer.
    • Tested BLM1500 data, video, and voice services for the Spirent Test Center.
    • Installed and supported Asterisk PBX for testing VoIP.
    • Configured extreme L3 Switches.
    • Troubleshot networks.
    • Tested GPON access to the network with ONT terminal provisioning.
    Technologies: GPON Broadband Access
  • Integration and Verification Engineer

    2008 - 2011
    Ericsson Nikola Tesla
    • Conducted support for test tools.
    • Tested Linux-based elements of Telephony Softswitch Solution 4.0.
    • Troubleshot and diagnosed network problems.
    • Conducted SIP protocol analysis.
    • Integrated site system testing via installation and configuration of TGC/MGW elements.
    Technologies: Telephony Switches
  • Network Administrator

    2007 - 2007
    Siemens PSE
    • Supported the introduction of multicast in the company network.
    • Created documentation for the network.
    • Diagrammed network connections.
    • Tested multicast on Cisco switches.
    • Tested multicast across routers.
    • Created final documentation and reported on test results.
    Technologies: Cisco


  • SIP Load Balancer (Development)

    A simple Java application which will do load balancing across several SIP servers, based on list, or periodic reports from SIP servers.

  • VoIP Call Recording System (Development)

    A Java-based back-end system for VoIP call recording that used Spring for back-end and Vaadin for UI.

    SIP, RTP protocols, compression using G.729 standard.

  • Blagajna (Development)

    A simple Java GUI application for issuing printed receipts on cashier systems, completed according to Croatian legislative requirements.

  • Simple Management System (Development)

    A simple management front-end application coded in Java FX, to demonstrate REST approach and FX user interfaces. Back-end PHP and SQL scripts are also provided for integration into Apache web servers with a PHP module and MySQL database.

  • Implementing a Remote Framebuffer Server in Java (Publication)
    Connecting to remote computers and working on them through terminals over a network is something we often take for granted. Technologies that enable us to do this have changed the way we work and have opened doors to amazing possibilities. Although the inner workings of these technologies may seem like obscure knowledge, implementations of many of these technologies are surprisingly straightforward. In this article, Toptal engineer Igor Delac gives us a step-by-step tutorial on how to implement the Remote Framebuffer server-side protocol in Java, allowing Swing-based applications to run and be interacted with remotely using standard VNC clients.


  • Paradigms

    Procedural Programming, Event-driven Programming
  • Platforms

    Linux, UnboundID
  • Languages

    Java, Assembler, Bash, SQL
  • Frameworks

    Spring 5, Vaadin
  • Tools

    Eclipse IDE
  • Other

    Multicast, LDAP, VoIP
  • Libraries/APIs

    Spring LDAP
  • Storage



  • Master's degree in Electrical and Software Engineering
    2002 - 2008
    J. J. Strossmayer University - Osijek


  • CCNA
    APRIL 2012 - PRESENT

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