Microsoft Teams External Calling & Session Border Controller Engineer

Ernst & Young Advisory Services Sdn Bhd; Taguig; On-site; PHP 1,200,000 - 1,800,000; Full time

Job summary

EY is seeking an experienced Microsoft Teams Voice Engineer to design, deploy, and optimize enterprise voice services, including External Calling, Direct Routing and Session Border Controllers. You will work across global locations with strong troubleshooting and stakeholder management skills.

The role requires hands-on SBC administration, SIP signalling expertise and a focus on service reliability, change control and automation using PowerShell.

Qualifications

• Eight+ years in UC/voice engineering or related field.
• Hands-on with Microsoft Teams Voice, Direct Routing or Teams Phone.
• Experience managing enterprise SBCs and carrier connectivity.

Responsibilities

• Design, implement and support Teams External Calling and Teams Phone solutions.
• Configure voice routing policies, dial plans, calling policies and emergency policies.
• Enable PSTN connectivity via Direct Routing and migrate PBX to Teams telephony.
• Deploy, manage and upgrade SBC infrastructure and ensure interoperability with carriers.
• Coordinate SIP trunks, DID management and PSTN activations with carriers.

Skills

Teams Voice

Direct Routing

Teams Admin Center

Voice routing

Dial plans

SBC management

Education

Bachelor's degree in engineering or related field

Tools

AudioCodes SBC

Ribbon SBC

Oracle SBC

Cisco CUBE

Job description

Microsoft Teams External Calling & Session Border Controller Engineer

Location: Taguig

Other locations: Primary Location Only

Date: 25 Sept 2026

Requisition ID: 1745047

At EY, you’ll have the chance to build a career as unique as you are, with the global scale, support, inclusive culture and technology to become the best version of you. And we’re counting on your unique voice and perspective to help EY become even better, too. Join us and build an exceptional experience for yourself, and a better working world for all.

JOB DESCRIPTION

Microsoft Teams External Calling & Session Border Controller Engineer

Recruitment profile for Teams Phone, Direct Routing, SIP and SBC engineering

Rank Supervising Associate / Assistant Director, based on experience

Service Line Enterprise Technology | Enterprise Communication & Collaboration

Location Philippines

Employment Type Full-time

The opportunity

We are seeking an experienced Microsoft Teams Voice Engineer with strong expertise in Microsoft Teams External Calling, Teams Phone, Direct Routing and Session Border Controller technologies. The role is responsible for designing, deploying, supporting and optimizing enterprise voice services while maintaining operational stability, regulatory alignment and a consistent user experience across global locations.

The successful candidate will combine hands‑on engineering capability with strong troubleshooting, stakeholder management and service ownership. The role requires practical knowledge of VoIP, SIP signalling, SBC platforms, carrier integrations, telephony migrations and Microsoft Teams Voice architecture.

Your key responsibilities

Microsoft Teams Voice and external calling

• Design, implement and support Microsoft Teams External Calling and Teams Phone solutions.
• Configure and manage Teams voice routing policies, dial plans, calling policies, emergency calling policies and caller ID policies.
• Enable and troubleshoot PSTN connectivity through Teams Direct Routing.
• Support migration from traditional PBX platforms to Microsoft Teams telephony.
• Configure and support Auto Attendants, Call Queues and user voice enablement.

Session Border Controller engineering

• Deploy, administer and maintain enterprise SBC infrastructure.
• Configure SIP trunks, routing rules, normalization and interoperability between Teams, carriers and telephony platforms.
• Troubleshoot SIP signalling and media issues using traces, logs and end‑to‑end call‑flow analysis.
• Perform SBC software upgrades, patching, certificate management, resiliency validation and failover testing.
• Maintain secure and highly available SBC configurations in accordance with change and release controls.

Voice infrastructure and carrier integration

• Coordinate SIP trunk provisioning, DID management, number porting and PSTN service activation with telecom carriers.
• Validate voice quality, routing, redundancy and disaster‑recovery capabilities.
• Lead technical troubleshooting with carriers, Microsoft and SBC vendors.
• Support regional and country telephony deployments, migrations and service transitions.

Operations, automation and service improvement

• Provide advanced L3/L4 technical support for Teams Voice and SBC services.
• Investigate call‑routing failures, one‑way audio, media‑quality degradation, policy errors and SBC incidents.
• Participate in major incident response, root‑cause analysis and corrective action planning.
• Automate recurring administration and validation activities using PowerShell.
• Create and maintain technical documentation, operational procedures, support playbooks and knowledge articles.
• Drive proactive monitoring, standardization and continuous service improvement.

Skills and attributes for success

• Area Required capability Microsoft Teams Teams Phone, Direct Routing, Teams Admin Center, voice routing, dial plans and calling policies
• SBC platforms Strong experience with AudioCodes, Ribbon, Oracle SBC or Cisco CUBE
• Voice technologies SIP, RTP/SRTP, TLS, VoIP, PSTN, number management and call‑flow analysis
• Microsoft platform Microsoft 365 administration, Entra ID and PowerShell
• Networking TCP/IP, DNS, DHCP, firewalls, NAT, QoS, LAN/WAN and network troubleshooting
• Diagnostics Teams Call Analytics, Call Quality Dashboard, Wireshark and SBC trace analysis
• Service management Incident, problem, change, major incident and vendor‑management practices

Experience and qualifications

• Eight or more years of experience in unified communications, collaboration or voice engineering.
• Eight or more years of hands‑on experience with Microsoft Teams Voice, Teams Phone or Direct Routing.
• Demonstrated experience managing enterprise SBCs and SIP carrier connectivity.
• Experience supporting production voice services and resolving complex incidents.
• Experience working with global stakeholders, telecom carriers and technology vendors.
• Bachelor’s degree in engineering, computer science, information technology or a related discipline, or equivalent practical experience.

Preferred certifications and knowledge

• Microsoft certification aligned to Teams administration or collaboration communications.
• AudioCodes, Ribbon, Oracle SBC or Cisco Collaboration certification.
• ITIL Foundation or practical experience in IT service management.
• Knowledge of emergency calling requirements such as E911 or E112.
• Experience with ServiceNow, monitoring platforms and telephony automation.

What we look for

• Strong analytical and structured problem‑solving skills.
• Clear written and verbal communication with technical and non‑technical stakeholders.
• Ability to work effectively across cultures, time zones and matrixed teams.
• Ownership mindset, attention to detail and commitment to service reliability.
• Ability to lead technical discussions, document decisions and coach junior engineers.

Measures of success

• Stable, secure and highly available Teams Voice and SBC services.
• Timely incident resolution and high‑quality root‑cause analysis.
• Successful carrier, SBC and country integration outcomes.
• Increased automation, standardization and operational efficiency.
• Positive stakeholder and end‑user experience.

Recruitment note: The final rank and scope should be calibrated to the candidate’s depth of architecture ownership, hands‑on SBC administration, global deployment experience and production support accountability.

EY | Building a better working world

EY exists to build a better working world, helping to create long‑term value for clients, people and society and build trust in the capital markets.

Enabled by data and technology, diverse EY teams in over 150 countries provide trust through assurance and help clients grow, transform and operate.

Working across assurance, consulting, law, strategy, tax and transactions, EY teams ask better questions to find new answers for the complex issues facing our world today.

EY refers to the global organization, and may refer to one or more, of the member firms of Ernst & Young Global Limited, each of which is a separate legal entity. Ernst & Young Global Limited, a UK company limited by guarantee, does not provide services to clients.