Voice Network Engineer

Insight Global; Greater London; On-site; GBP 52,000 - 75,000; Full time

Job summary

Insight Global is seeking a Network & Voice Engineer for a permanent role in London, with 3 days on-site at our client’s financial services organisation. The role focuses ~80% networking and ~20% telephony, handling design, implementation, maintenance, and support of enterprise network and voice infrastructure across multiple locations.

You will troubleshoot complex issues, contribute to architecture and capacity planning, and participate in vendor coordination and infrastructure refresh

Qualifications

• Strong experience with Cisco LAN/WAN/WLAN/VPN environments.
• Hands-on routing, switching, firewalls, and multi-site connectivity.
• Experience supporting enterprise voice and unified communications (SIP trunking, SBCs, call routing).
• Proven ability to monitor, troubleshoot, and resolve complex network/telephony issues.
• Knowledge of security, compliance, DR/BC planning, and documentation.
• Experience contributing to network architecture, capacity planning, and vendor mgmt.
• Strong communication and stakeholder management skills.

Responsibilities

• Design, implement, maintain, and optimise enterprise network and voice infrastructure.
• Support Cisco networking technologies including routing, switching, wireless, VPN, and firewall environments.
• Provide Tier 3 troubleshooting and escalation support for critical network and telephony incidents.
• Manage and optimise SIP trunking, voice platforms, and unified communications solutions.
• Support security, compliance, disaster recovery, and business continuity initiatives.
• Build and maintain relationships with vendors and service partners.
• Create and maintain technical documentation, standards and procedures.
• Contribute to network architecture, roadmaps, capacity planning, and technology refreshes.
• Participate in network refresh and infrastructure modernisation projects.

Skills

Cisco networking

LAN/WAN/WLAN/VPN

Routing & Switching

SIP trunking & VoIP

SBCs & Firewalls

Network security & continuity

Documentation & vendor mgmt

Tools

Python

Ansible

Job description

Insight Global are seeking a Network & Voice Engineer for a leading financial services organisation. This position requires 3 days onsite in London, England for a permanent opportunity.

The Network & Voice Engineer will be responsible for the design, implementation, maintenance, and support of the organisation's network, voice, and unified communications infrastructure. This role plays a key part in ensuring the availability, security, and performance of enterprise networking environments across multiple locations. The position offers the opportunity to take ownership of network refresh and infrastructure enhancement projects, working closely with vendors and stakeholders while contributing to strategic technology initiatives.

The role is approximately 80% networking-focused and 20% telephony-focused, supporting a modern enterprise environment and serving as a Tier 3 escalation point for critical incidents. Candidates should be comfortable participating in occasional after-hours support when required.

Must-Have Requirements Include:

• Strong experience supporting Cisco-based LAN, WAN, WLAN, and VPN environments.
• Hands-on expertise with routing, switching, firewalls, and multi-site network connectivity.
• Experience supporting enterprise voice and unified communications platforms, including SIP trunking, Session Border Controllers (SBCs), call routing, and provisioning.
• Proven ability to monitor, troubleshoot, and resolve complex network and telephony infrastructure issues.
• Knowledge of network security principles, compliance requirements, disaster recovery, business continuity planning, and technical documentation.
• Experience contributing to network architecture, capacity planning, technology upgrades, vendor management, and Tier 3 support functions.
• Strong communication and stakeholder management skills.

Plusses Include:

• Advanced networking expertise across BGP, OSPF, Multicast, VPN technologies, Cisco routers, switches, Firepower Threat Defence (FTD), Wireless LAN Controllers, and Access Points.
• Experience with VoIP technologies and voice infrastructure.
• Scripting and automation experience using Python, Ansible, or similar technologies.
• Previous experience within a fast-paced financial services environment.

Key Responsibilities:

• Design, implement, maintain, and optimise enterprise network and voice infrastructure.
• Support Cisco networking technologies including routing, switching, wireless, VPN, and firewall environments.
• Provide Tier 3 troubleshooting and escalation support for critical network and telephony incidents.
• Manage and optimise SIP trunking, voice platforms, and unified communications solutions.
• Support security, compliance, disaster recovery, and business continuity initiatives.
• Build and maintain relationships with network vendors, telecommunications providers, and service partners.
• Create and maintain technical documentation, standards, and operational procedures.
• Contribute to network architecture, infrastructure roadmaps, capacity planning, and technology refresh programmes.
• Participate in network refresh and infrastructure modernisation projects, including design, implementation, and vendor coordination.