VoIP NOC Support Engineer (Linux + SIP Expert)

Role & responsibilities

• Monitor real-time VoIP traffic including

  ACD, ASR, CPS

  , QoS metrics, latency, and call routing performance.
• Troubleshoot

  SIP, RTP, SDP

  , one-way/no audio, codec mismatch, call failures, and SIP error codes (4xx/5xx/6xx).
• Use

  Linux CLI

  for log analysis, system checks, service restarts, and network troubleshooting.
• Perform SIP call flow analysis using tools like

  sngrep

  ,

  tcpdump

  ,

  Wireshark

  , and interpret packet captures.
• Handle

  carrier routing

  , prefix updates, routing table management, and failover logic.
• Perform

  CDR analysis

  to identify call trends, failures, FAS, fraud patterns, and routing issues.
• Handle connectivity issues including

  IPSec VPN, NAT traversal, firewall rules

  , and interconnect tests.
• Monitor softswitch platforms such as

  VeriSwitch, Yeti-Switch, FreeSWITCH, OpenSIPS

  and escalate abnormalities.
• Create incident reports, perform RCA (Root Cause Analysis), and maintain proper documentation.
  
• Work on

  shift operations (24/7)

  ensuring SLA-bound response and continuous service availability.
• Coordinate with carriers, internal engineering, and management teams for issue resolution.

Preferred candidate profile

• Strong hands-on experience with

  Linux Administration

  and

  Linux CLI

  (Ubuntu/CentOS).
• Deep understanding of

  SIP, RTP, SDP

  , VoIP call flows, media negotiation, and troubleshooting.
• Practical knowledge of

  sngrep

  ,

  tcpdump

  ,

  Wireshark

  , and packet capture analysis.
• Experience working with softswitch platforms like

  VeriSwitch

  ,

  Yeti-Switch

  ,

  FreeSWITCH

  ,

  OpenSIPS

  (preferred).
• Good grasp of

  networking fundamentals

  : NAT, firewall rules, routing, IPSec VPN.
• Ability to handle

  VoIP routing

  , prefix management, and carrier interconnect testing.
• Analytical mindset with the ability to detect fraud, FAS, short-duration patterns, and abnormal traffic spikes.
  
• Familiar with

  CDR analysis

  , SLA monitoring, and NOC operations.
• Comfortable in a

  24/7 rotating shift

  environment.
• Strong communication skills for interaction with international carriers and internal teams.
  
• Fast learner, proactive, and able to work under pressure during high traffic windows.