Senior Network Engineer

Senior Network Engineer – VoIP / Real-Time Communications Practice by Numbers (PBN) | Gurugram / Kolkata, India About Practice by Numbers Practice by Numbers is a leading dental practice management SaaS platform serving over 1,500 dental practices across North America, providing practice management, VoIP telephony, payments, and advanced analytics. The platform is evolving into an AI-first product, adding conversational automation and intelligent communication workflows for patients and front-office teams. About the Role This role owns the network connectivity and real-time communications infrastructure that enables PBN's VoIP platform to reliably communicate with customer networks, SIP carriers, and the public internet. The engineer will be responsible for troubleshooting end-to-end VoIP connectivity and media issues across the entire network path — from customer phones and LAN infrastructure through switches, routers, firewalls, VLANs, Wi-Fi, VPNs and ISP connections, to PBN's SIP infrastructure and upstream carriers. This is a hands-on production troubleshooting role requiring strong networking fundamentals combined with a deep understanding of SIP, RTP, NAT traversal, and real-time communications. The engineer should be able to analyze SIP/RTP traffic at the packet level, determine where a signaling or media failure is occurring, and clearly guide a customer's IT/network team toward the appropriate resolution. The engineer will work closely with PBN's SIP/VoIP engineering team, customer IT teams, carriers, and support/operations teams to diagnose and resolve complex voice-quality, connectivity, registration, signaling, and media-path issues. Work Hours: 8:00 PM – 5:00 AM IST Key Responsibilities Own end-to-end network troubleshooting for PBN's VoIP traffic between customer environments, PBN's SIP infrastructure, and upstream carriers/PSTN networks. Diagnose SIP signaling and RTP media issues across customer LANs, firewalls, routers, switches, Wi-Fi networks, VPNs, ISP connections, and internet paths. Analyze SIP messages, SDP, RTP flows, packet captures, and network telemetry to identify the root cause of call failures and audio-quality issues. Troubleshoot common VoIP networking problems including NAT traversal, SIP ALG, asymmetric routing, blocked ports, firewall policies, RTP path failures, DNS issues, packet loss, jitter, latency, andnetwork instability. Work directly with customer IT/network teams to identify problems within their network and provide clear, technically accurate remediation guidance. Guide customers through configuration and troubleshooting of switches, routers, firewalls, VLANs, DHCP, Wi-Fi, VPNs, ISP connectivity, QoS, and related network infrastructure required for reliable VoIP service. Validate network readiness for PBN VoIP deployments, including connectivity, port accessibility, NAT behavior, SIP signaling, RTP media paths, and network quality. Troubleshoot SIP…