Technical Specialist, Fixed Voice

Singtel Group; Sydney; Hybrid; AUD 140,000 - 200,000; Full time

Benefits offered by this job

Flexible working arrangements

On-site childcare

Employee discounts

Counselling services 24/7

Discounted Optus products

Job summary

Optus is seeking a Senior Technical Specialist for Fixed Voice to oversee operation, maintenance and continual improvement of the Fixed Voice network. You will work across Ribbon platforms, manage SIP trunking, and drive observability and automation in network tooling.

You will bring 15+ years in fixed telecoms, deep Ribbon/CS2K knowledge, and strong incident management skills, with Hybrid work options and a focus on reliability and change governance.

Qualifications

• 15+ years of wireline or Fixed Voice telecommunications experience.
• Hands‑on experience with Ribbon or GENBAND platforms.
• Deep knowledge of CS2000 (CS2K), C20 and SBC platforms.

Responsibilities

• Operate and maintain Ribbon Fixed Voice nodes.
• Provide Level 2 fault management and incident resolution.
• Manage escalated faults across Enterprise and Wholesale environments.
• Perform structured fault diagnosis and root‑cause analysis.
• Configure and manage C20 elements and SIP trunking.
• Investigate voice network faults using SIP, INAP, Diameter, RTP and C7/ISUP.

Skills

Wireline Fixed Voice

Ribbon/GENBAND platforms

SIP trunking

Incident management

Troubleshooting OSIX/Wireshark

Grafana Kalix

Education

Bachelor's degree in Telecommunications or related

Tools

Grafana

Kalix OSIX

Wireshark

Ribbon EMS/RAMP

ServiceNow

Unix/Linux

Job description

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Optus is an Australian telecommunications company, delivering more than 11 million services to our customers every day across mobile, broadband and digital solutions.

As the Technical Specialist, Fixed Voice, you’ll be accountable for the operation, maintenance, technical support and continual improvement of Optus’ Fixed Voice network infrastructure. You’ll work across Ribbon voice switching and SBC platforms to maintain network availability, performance, resilience and operational compliance, while helping modernise our Network Operations tooling through improved observability, trusted data, OSS integration and automation.

What You’ll Do

• Operate and maintain Ribbon Fixed Voice nodes, including DMS300, CS2000 (CS2K), C20, SBC, PSX, IN and associated sub-elements.
• Provide Level 2 fault management, incident resolution and technical support for Fixed Voice platform outages, service degradations and complex operational issues in line with ITIL best practices.
• Manage escalated and complex customer-related faults across Enterprise and Wholesale environments.
• Perform structured fault diagnosis and root‑cause analysis, identifying corrective actions and validating the effectiveness of permanent remediation.
• Configure and manage C20 elements, including GWC, SP2K, G9, MAS, SST, SSL/SESM/A2, CBM, CMT, IEMS, MG15K and NDM.
• Manage SIP trunking, routing and policy rules through Ribbon NMS, including SIP/TDM interworking and service validation.
• Investigate voice network faults using SIP, INAP, Diameter, RTP and C7/ISUP protocols, together with OSIX and Wireshark.
• Execute software upgrades, patch management and planned maintenance on Ribbon platforms, including implementation, testing, rollback and post‑change verification.
• Monitor Fixed Voice network KPIs using Grafana and Kalix, proactively addressing degradation trends affecting call completion, ASR, NER and MOS.
• Develop, review and maintain Methods of Procedure, implementation plans, risk assessments, technical change records, network documentation and knowledge articles.
• Collaborate with Network Operations, Engineering, Service Management, NOC, Network Enablement & AI Ops, vendors and suppliers to restore services, improve reliability and support the transformation and rationalisation of Network Operations tooling.

What You Bring

• 15+ years of wireline or Fixed Voice telecommunications experience, with hands‑on operational experience across Ribbon or GENBAND platforms.
• Deep technical expertise in CS2000 (CS2K), C20 and SBC platforms, including call control, provisioning, trunk management, signalling configuration and fault resolution.
• Strong operational knowledge of Ribbon Fixed Voice architectures and SBC platforms, including SIP trunking, media policy and SIP/TDM interworking.
• Advanced knowledge of SIP, SS7/ISUP, SIGTRAN, TDM E1/PRI, RTP/RTCP, G.711/G.729, DTMF, LNP/ENUM and IPv4/IPv6.
• Practical experience with Grafana, Kalix/OSIX, Wireshark, Ribbon EMS/RAMP, ServiceNow or equivalent ITSM platforms, and Unix/Linux command‑line tools.
• Ability to interpret Fixed Voice KPIs, including call completion rate, ASR, NER and MOS, and act on emerging degradation trends.
• Proven experience in incident management, root‑cause analysis, planned maintenance, software upgrades, patching, MOP development, change governance and vendor TAC engagement.
• A Bachelor’s degree in Telecommunications, Electronics, Computer Science or equivalent experience. Ribbon certifications, CCNA/CCNP Voice and ITIL v4 Foundation are preferred.
• Knowledge of observability, operational analytics, automation and safe AI‑assisted operations is desirable.
• Strong technical ownership, accountability and a disciplined approach to operational risk, with the ability to communicate complex issues clearly to technical and non‑technical stakeholders in high‑pressure incident, outage and escalation environments.

The good stuff…

• Competitive remuneration and employee discounts. Make life easier (and more affordable) with $80 monthly credit and 25% off Optus products and unique shopping discounts with our retail partners.
• Flexible working arrangements with opportunities to work three days in the office, two days remote or home.
• Vibrant and collaborative office campus that includes cafes, convenience store, chill out zones, GP, post office, gym and on‑site childcare centre.
• Competitive leave policies, including additional 'Connected’ days to focus on culture, family, health, community, or whatever’s important to you.
• We support growing families with inclusive, carer‑neutral paid Parental Leave of up to 16 weeks.
• Build meaningful connections through employee‑led networks and diversity initiatives including Culture Connect, Elevate Women, Disability Network and Express Yourself (LGBTQIA+).
• Put your wellbeing first with free access to counselling and support services, 24/7 — in‑person, by phone, SMS, or video.
• Free Optus bus from Macquarie University Metro Station (every 6-8 minutes); morning and afternoon.

At Optus, we are strengthened by others and that means valuing diversity and saying ‘yes’ to embracing individual differences.

We are committed to ensuring that our application process provides an equal employment opportunity to all job seekers, including individuals from diverse gender, cultural and linguistic backgrounds, individuals with a disability, individuals identifying as being part of the LGBTQIA+ community, individuals who may have served in the armed forces or who identify as Aboriginal and/or Torres Strait Islander.

We also want to do our best to make our recruitment process inclusive.

If you require any adjustments or accessibility support to participate fairly and equitably in the recruitment process, please email [e-mail] or call 1800 309 170.