Senior Asterisk & VoIP Systems Engineer

About the role

Turkcell is looking for a Senior Asterisk & VoIP Systems Engineer to play a key role in the development, integration, operation and technical support of Enterprise PBX, Call Center and Unified Communications platforms. The role covers both application and infrastructure layers, end-to-end technical analysis and Root Cause Analysis (RCA), highly available systems and operational automation. It is not a GUI-focused PBX administration role (FreePBX, Issabel, Elastix, etc.); hands-on experience with Pure Asterisk in production is required.

Key responsibilities

• Manage installation, configuration, operation, integration and support of Enterprise PBX, Call Center and UC platforms, and take part in designing and deploying Pure Asterisk systems.
• Integrate CRM, ERP and internal applications using Dialplan, AGI, AMI and ARI.
• Compile Asterisk from source, manage modules, patching, upgrades and migrations, and configure Asterisk Realtime Architecture (ARA).
• Configure SIP trunks, SBCs and FXO/FXS/PRI gateways, and integrate SIP/VoIP with telecom operators and ITSPs.
• Deploy and run Kamailio/OpenSIPS for SIP proxy and routing, and use Wireshark, tcpdump and sngrep for packet-level analysis and RCA.
• Troubleshoot VoIP issues such as jitter, packet loss, latency, one-way audio, RTP, codec negotiation, DTMF and call setup failures.
• Administer Red Hat Enterprise Linux servers and support Java/Tomcat applications and JVM issues.
• Use Elasticsearch for centralized logging, Zabbix/SolarWinds for monitoring, and contribute to load balancing, HA, failover and disaster recovery.
• Work on incident, problem and change management, write technical documentation and runbooks, and work with software, DevOps, system, network and telecom teams.

Required profile

• Bachelor's degree in Computer Science, Software Engineering, Telecommunications Engineering or a related field.
• 5+ years of hands-on experience designing, developing and operating high-traffic Asterisk-based PBX, Call Center or VoIP platforms.
• Digium Certified Asterisk Professional (dCAP) or current Sangoma/Asterisk certification preferred; CCNA/CCNP Collaboration or Linux certifications are a plus.
• Comfortable in critical, 24/7 environments and willing to join an on-call rotation.

Required skills

• Pure Asterisk, SIP, PJSIP, SDP, RTP/RTCP, SIP trunks, SBCs and FXO/FXS/PRI gateways.
• Dialplan, AGI, AMI, ARI and Asterisk Realtime Architecture.
• Red Hat Enterprise Linux, Bash/Shell scripting, TCP/IP, DNS, NAT, VLAN, QoS and packet analysis.
• Nice to have: Kamailio/OpenSIPS, Docker/Kubernetes, Elasticsearch, Zabbix, MySQL/PostgreSQL, Azure DevOps/TFS.