Support Needed for Asterisk PBX

We need Asterisk PBX support to figure out, analyze and troubleshoot existing configurations that belong to our customers. We will be awarding continuous projects in blocks of 10 hours of support. We need a VoIP professional who has - a clear understanding of how VoIP protocols like SIP work, - considerable experience designing, setting up, operating, troubleshooting FreePBX, Asterisk and other embedded VoIP equipment, - Linux administration skills to install, troubleshoot and maintain third party software tools like Queumetrics, - skills to occasionally get involved in router/switch configurations and other devices like Cisco ASA that exist in current network setups, - great written and oral communication skills. The support will include - communication over Skype to analyze customer problems and propose solutions, - remote connection to customer systems using ssh and other means to implement and test the solutions, - provide expert advice for system improvements and customer requests, - provide detailed documentation on jobs completed, Some Issues of Critical Importance - Our customers include a lot of call centers who need high availability systems. Thus, work usually needs to be performed on live systems. - Some maintenance jobs may require working out of working hours. Thus, working at weekends and after working hours may be required.