Job Description: We are seeking an experienced Unified Communications (UC) / Voice Network Engineer with strong Cisco CUCM expertise to support and deliver enterprise telephony and contact center migrations, including Genesys and Vonage platforms. The role will focus on network and voice readiness, SIP/voice integration, call routing, number management, cutover planning, and stabilization across multiple sites and user groups. You will partner with network, security, service desk, vendors, and business stakeholders to ensure a seamless migration with minimal disruption, while maintaining high availability, quality, and compliance. Key Responsibilities: CUCM / Cisco UC Core Administer and engineer Cisco CUCM (clusters), Unity Connection, IM&P (if applicable), and related UC components. Configure and manage: SIP trunks, route patterns, route lists/groups, translation patterns Partitions/CSS, device pools, regions/locations, SRST Endpoints (Cisco IP phones, softphones), firmware loads, and device templates Support moves/adds/changes (MAC) and resolve complex L2/L3 voice incidents. Perform dial plan design/optimization, calling search space design, and normalization. Genesys Migration (Contact Center) Support migration activities to Genesys (e.g., Genesys Cloud CX or Genesys Engage depending on environment): Telephony integration and call routing design SIP integration, DID mapping, IVR/queue routing dependencies (as applicable) Testing (inbound/outbound flows, DTMF, recording, transfers, consult, conferencing) Collaborate with contact center teams on cutover planning, agent readiness, and issue triage. Vonage Migration (UCaaS / SIP / Carrier) Deliver integration/migration to Vonage services (UCaaS, SIP trunking, or communications APIs as applicable): SIP trunk provisioning/interop, codec negotiation, TLS/SRTP design (where used) Number porting coordination (DIDs, toll-free), carrier testing, failover planning Call quality baselining and post-cutover stabilization Network Readiness & Voice Quality Drive network readiness for voice/contact center migrations: QoS (DSCP marking, trust boundaries), WAN/LAN readiness, jitter/latency/packet-loss analysis Firewall/NAT design, SIP ALG considerations, SBC connectivity requirements DNS, DHCP (Option 150), NTP, routing, multicast (if used) Use tools for troubleshooting and quality monitoring (e.g., packet captures, CUCM RTMT, SBC logs, voice MOS). Cutover, Testing, Documentation Create and execute: Migration runbooks, cutover plans, rollback plans, and test scripts Lead or support: UAT, pilot migrations, production cutovers, and hypercare Maintain clear documentation: High-level designs (HLD), low-level designs (LLD), dial plan documentation, SOPs Stakeholder & Vendor Management Work with: Network/Security/Identity teams, service desk, field support Vendors/carriers (Genesys/Vonage, SIP providers, SBC vendors) Communicate progress, risks, dependencies, and mitigation plans clearly. Required Skills & Experience 10 years enterprise experience in Cisco UC/Voice engineering. Strong hands-on experience with: Cisco CUCM, SIP trunking, dial plan/routing, device provisioning Voice gateway technologies (e.g., CUBE, ISR voice gateways) and/or SBC concepts Proven experience supporting at least one of: Genesys contact center migration/integration (Cloud or on-prem) Vonage UCaaS/SIP trunking migration/integration Excellent troubleshooting skills across: SIP call flows (INVITE/200 OK/ACK/BYE), codec issues, one-way audio, DTMF, transfers Network fundamentals for voice (QoS, NAT/firewalls, routing, DNS/DHCP/NTP) Experience with migration delivery: Cutover planning, testing, rollback, hypercare, and BAU transition