VoIP debugging and troubleshooting, ISDN debugging and troubleshouting, hardware based PBX and Asterisk based PBX configuration. Integration Panasonic & LG PBX'es with Asterisk via PRI/VOIP inetrfaces. Cisco and Addpac routers with PRI, GSM (cellular), VoIP configuration and troubleshooting. NAT passthrough configuration for voice traffic. IP-phones bulk configuration and provision. More then 15 years expirience in PBX'es and telephony. Certified engineer for Panasonic and LG PBX'es from dinosaurus to last generation VoIP IP-PBX'es including microcell SIP-DECT system. Did projects with up to 100 PBX integration to one network with Asterisk as central switch. Equipment skills and knowledges. Asterisk, FreePBX, Elastix. CRM Inegration. VoIP Troubleshooting including transport ans signaling. Panasonic PBX'es: KX-T206, KX-TA308, KX-TA616, KX-TEB308, KX-TES824, KX-TEM824, KX-TDA100, KX-TDA200, KX-TDA600, KX-TDE100, KX-TDE200, KX-TDE600, KX-NCP500, KX-NCP1000, KX-NS500, KX-NS1000, KX-UDS124. LG PBX'es: GHX-36, GHX-616, GHX-46, LDK-100, LDK-300, ipLDK-60, ipLDK-100, ipLDK-300, IPECS-MG, IPECS-LIK, IPECS-eMG80, Aria SOHO Other equipment: Linksys/Cisco VoIP gateways and IP-phones, Addpac VoIP and VoIP2GSM gateways, Panasonic, Mediant, Snom, Yealink, Digium IP-phones and a lot of different VoIP equipment from different vendors.