VoIP How to install Homer using yum command.
Homer is work on Web browser.It able to showing lists of CDRs and displaying SIP flow for each call.And you can see raw SIP packet for each call from browser.
Technology
VoIP 
Cloud Microsoft Azure: In case of 2 NICs receiving same packets same time.
Explain about accelerated networking function of Azure.
Linux Linux shell: Using xargs with put argument to specified place
Explain for Using xargs with option -i for put argument to specified place.
ZABBIX/Monitoring How to send ping from zabbix-agent
There is a demand for ping monitoring from monitoring to another target.I will explain how to send ping from monitored host using UserParamater.
Linux How to make newline for bash output on CGI/bash
Run Linux commands from a website using CGI and see the results. It also explains how to deal with multi-line output.
ZABBIX/Monitoring How to install ZABBIX Proxy on CentOS
ZABBIX Proxy is a child ZABBIX Server without GUI.Proxy collects information from monitoring targets that cannot be directly accessed from ZABBIX Server (cannot access ZABBIX Server) and sends it to parent ZABBIX Server.
VoIP How to decode SIP/TLS with Wireshark and Decrypting SRTP
IP-PBX that communicates with SIP may use UDP or may be encrypted with TCP/TLS.If it's encrypted, you can't see it with Wireshark.You can see decrypted SIP packets with importing key to Wireshark.
ZABBIX/Monitoring Monitoring for Asterisk by ZABBIX using AMI
I will explain how to monitor SIP server Asterisk from ZABBIX using AMI (Asterisk Manager Interface).
