Panagiotis Kostaras

Experience

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  Hellenic Army

  Sept 2008 - Aug 2009

  System and Network Administrator

  My responsibilities include:• Maintaining and monitoring Hellenic Army’s servers, applications and network infrastructure• Local and Wide Area Network (LAN/WAN) administration, maintenance and upgrade/expansion (cabling)• Users' accounts management and configuration using Active Directory Domain Servers• Network and IT support during military training exercises• Help-desk duties involving hardware/software/network troubleshooting/installation and technical support/repair

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  Nokia

  Sept 2009 - Nov 2016

  Held multifaceted responsibilities to configure, install and administer network infrastructure optimized for various Nokia products. My responsibilities include:• Handling requests in complex IPv4/IPv6 Packet Core networks and MPLS L3VPN backbone• Designed and deployed networks using dynamic routing protocols (OSPF and BGP)• Work for permanent solution on reoccurring network incidents.• Identifying, diagnosing, and resolving network issues in a timely manner.• Documenting network changes and updating diagrams accordingly• Installation, configuration and administration of Unix-Based Systems (Solaris, Linux), FTP, DNS, DHCP, TFTP, Windows server 2012 under various LAN environments.• Working on Jira ticketing system to address developers/testing teams network related issues.• Conduct knowledge transfer trainings to newly hired resources in the teamDevices used:• Cisco routers 7600, 3900 series• Cisco switches 6500, 4500, 3800, 3700, 2900 series• Juniper MX480, EX4550, EX4200, SSG 550• Alcatel 7750 SR7 Show less The position involves Packet Core (MME and SGSN) end-to-end Network Verification. My responsibilities include:• Design, implementation and maintenance of MME network infrastructure• Initial bring up of the network element, L2/L3 configuration of the onboard switching units, integration with EPC elements (HSS, HLR, MSS, EIR, S-GW, LIC/LIB, NetAct, Traffica etc.) and connectivity establishment with radio BTS modules (2G/WCDMA/LTE) • Test strategy, planning and execution for test cases involving interfaces, protocols and network layer services, focusing on correct functionality• Technical documentation preparation (Test Specification, Test Plan, etc.) • Cooperation with Solution Engineers and Architects to design and prepare test environment and test strategy for Nokia PS products portfolio• Provide customer support when R&D involvement is requested• Coaching more junior members of the team and provide IP trainings during their enabling process Show less I have worked in the VoIP department for hiQ4200 and hiQ4300 products. My responsibilities include:• Performance testing, functional testing and reporting within an agile environment • Support test environment setup and operations • Customer cases fault replication and solution testing according to customer requirements and configuration• Managing network infrastructure optimized for VoIP applications (VoIP Soft-switch hiQ4200, VoIP Application Platform hiQ4300) • Router/switch configuration supporting lab testing equipment (Cisco 7609-S/4506/3750/2960, Juniper EX4200, Extreme networks switches) Show less

  • Network Engineer

    Jan 2014 - Nov 2016

  • Network Verification Engineer

    Oct 2012 - Dec 2013

  • System Verification / Lab support engineer

    Sept 2009 - Sept 2012
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  EuroEnergy

  Nov 2016 - Dec 2019

  IT Manager

  Main duties and responsibilities: ▪ IT and telecommunication systems administration of the offices and operational energy projects in 6 countries (UK, Spain, Greece, Latvia, Romania and Cyprus). ▪ Designing, procuring, installing, configuring, maintaining and repairing the Group's IT and telecommunication network to adhere with Group IT policy. ▪ Responds and acts to inquiries from employees, management and external partners to provide technical assistance and support.

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  GasLog Ltd.

  Jan 2020 - Aug 2021

  Senior Network Security Engineer
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  QUALCO

  Sept 2021 - now

  Information Technology Team Lead