VOIP Developer

Responsibilities:

• Design and develop scalable solutions to deliver reliable SIP services to a multitude of distributed endpoints including on premise Call Processing Servers, SIP proxy servers, handsets, and soft-phones.
• Enhance and maintain existing code and participate in design reviews and code reviews with other team members.
• Create custom provisioning tools to automate configuration of voice stack
• Participate in projects intended to improve infrastructure, including the integration of new systems and software
• Draft technical documentation
• Facilitate knowledge transfer to deployment and support teams
• Work with the Production Services and Support leaders towards keeping Service Availability above target.
• Other duties as assigned by management

Tools and Technologies used include:

• SIP protocol and its use in VOIP Services
• SIP proxies and/or SIP PBXs preferably open source products like Kamailio (OpenSER), FreeSWITCH, Asterisk, and FreePBX etc.
• Networking with Switches, Routers, Firewalls, IPSs and Security Appliances
• Programming experience with PHP / Perl / JAVA / C and custom modules with open source products
• Relational Databases ( MySQL), JDBC / ODBC
• Linux server operations, deployment and performance monitoring and shell scripting

Qualifications:

Education / Training:

·       University degree in Computer Engineering, Computer Science or equivalent.

Mandatory Skills & Experience:

• Experience coding and debugging Asterisk source code.
• Highly proficient in PHP, Perl and MySQL
• Knowledge of software design best practices.
• Proficient using source code management systems.
• Proficient understanding of SIP, MGCP, H323.
• Strong understanding of a hosted, highly available environment.
• Proficient with configuring Asterisk, including writing dialplan and custom application code.
• Knowledge of common configuration methods of endpoints (TR-069, HTTPS, TFTP).
• Working knowledge of T1/E1/J1 interfaces, PRI/EuroISDN, CAS, R2 and other protocols.
• Working knowledge of Analog Telephony interfacing.
• Familiarity with Linux system administration.

·       Familiarity with SQL Cluster configuration and administration (MariaDB/Galera a plus).

·       Experience with a moderately complex AWS or similar environment, including: VPC, subnetting in AWS, managing EC2 instances.

·       Experience with formal change management.

·       4+ years of experience developing VoIP Applications and Integrations.

Nice to have:

• Solid understanding of Telecommunications best practices.
• Working knowledge of SAN environments, a plus.
• Experience inspecting network traffic from a voice perspective a plus.
• Experience trouble shooting cooper, optical and wireless backbone a plus.
• Experience using Visio or similar applications to build network, telecom and call flow diagrams a plus.
• Experience configuring Kamailio SIP or similar server is a plus.
• Experience configuring Oracle Acme packet SBC is a plus.
• Experience with DevOps tools and methodologies, particularly with Puppet is a plus.
• Experience with various Property Management System (PMS) interfacing and development a plus.
• Experience with Hospitality Call Accounting interfacing a plus.
• Knowledge of wire shark or similar products a plus.
• Familiarity with enterprise monitoring and logging platforms (Zabbix, Nagios, Cacti, etc) a plus.
• Familiarity with basic layer 2/3 networking, including subnetting, assigning IPs, etc. a plus.

Personal Attributes:

·       Possess excellent written and verbal communication capabilities.

·       Problem solver that can work both independently and as a member of a team.

·       Ability to work well under pressure in a constantly changing environment with minimal supervision.

·       Driven by intellectual curiosity and focused on excellence in service delivery.