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Parambir Singh

VoIP / Telecom Systems Engineer

Architecting, securing, and scaling cloud-based telecom systems — from raw SIP/RTP packets to multi-tenant Cloud PBX orchestration.

GitHub → LinkedIn
4+Years in VoIP
22OSS Projects
7+Telecom Platforms
NSE 7Fortinet Certified
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// Summary

VoIP engineer with deep expertise in architecting, securing, and scaling cloud-based telecom systems. I specialize in SIP signaling, RTP media flows, TLS/SRTP encryption, NAT traversal, SBC logic, SIP trunking, multi-tenant Cloud PBX, and advanced VoIP endpoint provisioning.

Highly skilled in PCAP analysis, Wireshark, tshark, sngrep, Homer/HEP, SIP ladder debugging, and end-to-end network failure investigation — from packet-level tracing to protocol-level troubleshooting across distributed, high-availability environments.

Experienced building and optimizing FreeSWITCH and Asterisk platforms, integrating REST APIs, managing CDRs with database backends, and engineering call flows for enterprise and carrier-grade deployments. Strong foundation in C programming, performance tuning, and telecom automation.

// How I Work

01

Diagnose at the packet level

I don't guess at call quality issues — I capture, read the SIP ladder, and find the actual root cause before touching config.

02

Defense in depth

Every system I build has at least two independent layers protecting it — a fast path and a slow path, never a single point of failure.

03

Document the why, not just the what

Config without reasoning rots. Every repo I ship explains the trade-off behind each decision, not just the syntax.

// Skills

Protocols & Signaling

  • SIP / RTP
  • TLS / SRTP
  • NAT Traversal
  • SBC Logic
  • SIP Trunking
  • rtpengine

Platforms

  • FreeSWITCH
  • Asterisk
  • Kamailio
  • pjsip
  • 2600Hz / KAZOO
  • FusionPBX
  • Bicom Systems (PBXware / gloCOM)
  • Multi-tenant Cloud PBX
  • SIP Multicast Paging
  • Multi-vendor Auto-Provisioning (Yealink/Cisco/Grandstream/Avaya/Snom)

Diagnostics

  • Wireshark / tshark
  • sngrep
  • Homer (HEP)
  • PCAP analysis
  • SIP ladder debugging

Security & Network

  • Fortinet / FortiGate
  • Cloudflare Tunnel / Zero Trust
  • fail2ban
  • Fraud/ghost-call detection

Cloud & Infra

  • AWS (API Gateway, Lambda, DynamoDB, ECS Fargate, RDS)
  • Docker
  • Linux administration
  • PostgreSQL
  • Nginx
  • DNS

DevOps & IaC

  • Terraform (modular AWS stacks)
  • Kubernetes / Helm
  • GitHub Actions CI/CD
  • OIDC-federated AWS deploys
  • Autoscaling (HPA / target-tracking)

Engineering

  • C programming
  • Python
  • REST APIs
  • Telecom automation
  • CDR / Billing pipelines
  • Bash
  • Git

// Platforms I've Deployed

FreeSWITCH Asterisk Kamailio FusionPBX 2600Hz / KAZOO Bicom Systems PBXware Bicom Systems gloCOM pjsip

// Featured Projects

terraform-aws-infra-modules

Reusable Terraform modules for a VPC + ECS Fargate service + RDS Postgres reference stack — least-privilege security groups, autoscaling, secrets in Secrets Manager, never in state as plaintext.

TerraformAWS

cicd-pipeline-aws-ecs

A working GitHub Actions pipeline: lint → test → build/push to ECR → deploy to ECS Fargate via OIDC federation, with automatic rollback on a failed deployment.

GitHub ActionsCI/CD

k8s-helm-service-deploy

Production-shaped Helm chart — Deployment, HPA, PodDisruptionBudget, Ingress, locked-down non-root securityContext — deploying the same image as the ECS pipeline, for a direct ECS-vs-Kubernetes comparison.

KubernetesHelm

kamailio-sbc-router

Multi-tenant SIP Session Border Controller: NAT traversal via rtpengine, TLS/SRTP termination, carrier failover via dispatcher.

KamailioSBC

freeswitch-cloud-pbx

Multi-tenant FreeSWITCH dialplan, ESL-driven REST automation API, and a real-time CDR pipeline into PostgreSQL.

FreeSWITCHREST API

pjsip-sip-diagnostics

A pjsua2-based SIP diagnostic client: registration latency, call setup time, and live RTP jitter/loss stats.

pjsipDiagnostics

aws-mobile-call-api

Serverless API Gateway + Lambda + DynamoDB backend for a mobile Cloud PBX app's click-to-call and call history.

AWSServerless

telecom-stack-docker

Containerized telecom stack: Kamailio + FreeSWITCH + PostgreSQL + Homer (HEP) call-flow monitoring.

DockerInfra

linux-voip-ops-toolkit

Trunk health checks, rotating SIP packet capture, system health reports, and automated CDR backups.

LinuxOps

kazoo-crossbar-client

A Python client for 2600Hz's KAZOO platform Crossbar REST API — accounts, devices, and call origination.

2600Hz / KazooAPI Client

ghost-call-defense

Detection and mitigation for nuisance/ghost SIP calls and scanning traffic at the SBC layer.

SecurityKamailio

fortinet-voip-firewall

FortiGate config for SIP/RTP: the SIP ALG problem, firewall policy, and voice traffic QoS prioritization.

FortinetNetwork Security

cloudflare-tunnel-voip-access

Secure Cloud PBX admin access via a named Cloudflare Tunnel + Access (Zero Trust) policy — no exposed admin port.

CloudflareZero Trust

voip-phone-provisioning-guides

Auto-provisioning guides + example configs for Yealink, Cisco, Grandstream, Avaya, and Snom desk phones.

ProvisioningMulti-vendor

voip-call-parking-announce

FreeSWITCH call parking with an automatic spoken slot announcement over overhead paging.

FreeSWITCHLua

multicast-paging-system

SIP multicast overhead paging across Yealink, Snom, Grandstream, and Cisco desk phones — one page, every phone, instantly.

MulticastMulti-vendor

voip-phone-unlock-guide

Vendor-lock removal guide for repurposing owned/decommissioned desk phones across major PBX platforms.

ITADRefurbish

ai-voice-agent

Real-time conversational AI agent that auto-answers FreeSWITCH calls: speech-to-text, LLM, text-to-speech, streamed live.

AIFreeSWITCH

teams-sip-bridge

Bridges Microsoft Teams Direct Routing to an on-prem SIP/FreeSWITCH Cloud PBX core.

Microsoft TeamsKamailio

yealink-remote-phonebook

Live, server-generated company directory for Yealink desk phones via Remote Phone Book.

YealinkProvisioning

sip-pcap-analyzer

Parses SIP pcap captures into a per-call summary: Call-ID, status, setup time, duration.

WiresharkPython

voip-troubleshooting-playbook

A structured runbook for diagnosing one-way audio, jitter, registration failures, and dropped calls.

RunbookDiagnostics

// Experience

VoIP Engineer / Telecommunications Technician

Nov 2021 — Present

Cloud Telecom & UCaaS Services Provider · Canada (On-site)

  • SIP trunking and multi-tenant Cloud PBX support for enterprise and carrier-grade voice traffic
  • FreeSWITCH/Asterisk platform engineering and call-flow design
  • Packet-level troubleshooting (Wireshark, sngrep, Homer/HEP) for distributed, high-availability voice infrastructure

IT Support Specialist

Oct 2020 — Apr 2021

BECCOS India · New Delhi, India

  • C programming and TCP/IP networking fundamentals

Electrical Engineer

Sep 2018 — Dec 2019

Energy Efficiency Services Limited · Noida, India

// Certifications

NSE 7

Fortinet NSE 7 — Enterprise Firewall, 7.6 Administrator

Fortinet Certified Associate/Expert track · Verified on Credly →
AWS

AWS Certified Cloud Practitioner

Amazon Web Services · Verified on Credly →
N+

CompTIA Network+ ce Certification

CompTIA · Verified on Credly →

// Education

B.E., Electrical and Electronics Engineering — Sant Longowal Institute of Engineering and Technology (2014 – 2018)