Senior SIP/VoIP Engineer – Voice Platforms (Onsite: PA/NJ/CO)

Our client is seeking a Senior Voice/VoIP Engineer with deep SIP expertise and strong hands‑on experience designing, troubleshooting, and supporting large‑scale voice platforms. This role requires the ability to translate business requirements into complete SIP‑based voice solutions and operate with a high degree of technical autonomy. The position is fully onsite at one of the listed locations.

Onsite | No Visa Sponsorship | No Relocation Assistance Contract Duration : 12 months | W2 Locations: Philadelphia, PA | Mount Laurel, NJ | Denver, CO Local candidates only (within ~1 hour commute) or those willing to relocate at their own expense Requirements: Design and support SIP‑based voice and VoIP solutions, including call flows, integrations, and multi‑site deployments. Troubleshoot complex SIP signaling and media/RTP issues across multiple systems and components. Translate business and functional requirements into technical voice architecture and integration designs.

Perform system level diagnostics across SBCs, carriers, networks, and application servers. Collaborate with engineering teams during design reviews, escalations, testing, and certification efforts. Develop or enhance automation scripts to improve operational efficiency and repeatability.

Utilize APIs (REST or SOAP) for integration, provisioning, or workflow automation. Produce technical documentation, design artifacts, and troubleshooting runbooks as needed. Qualifications (Must-Haves) 10+ years of hands‑on experience in Voice/VoIP engineering.

System level problem‑solving skills across multi‑component voice infrastructures. Deep expertise with SIP protocols, signaling, call flows, SDP, and RTP troubleshooting. Strong proficiency with Linux (CLI diagnostics, system‑level troubleshooting, packet capture tools) Experience with VoIP platforms such as PBX systems, SIP trunking, or service‑provider voice environments.

Basic scripting experience (e.g., Bash, Python) to support automation and operational tasks. Experience working with APIs (REST or SOAP) for integrations or operational tooling. Ability to work independently, make technical decisions, and own outcomes in complex environments.

Preferred Skills: Exposure to BroadWorks/BroadSoft or other carrier‑grade voice platforms. Experience supporting large‑scale, multi‑region or multi‑country voice deployments. Familiarity with Cisco voice technologies is acceptable, but this role requires SIP‑centric engineering rather than UCCX‑focused experience.

Experience with Session Border Controllers such as Oracle/Acme Packet, Ribbon, or Audiocodes.