Following is a portion of the configuration for an example access list: access-list permit tcp host New rules will inherit the Global Default. To disable SIP Fixup on Cisco devices you must issue the following commands: fixup protocol sip fixup protocol sip udp Access lists or conduits may be helpful. Port is what 3CX require opening on the firewall which has been done bu the firewall checker in 3CX reports that the port is being translated to something else.īecause this is a default setting, no indication of it being on or off is visible in the configuration. I only get this issues with voip-unlimited as it works OK with sipgate. The 3CX system is installed on a Win XP Pro PC as reccommended and we have also tried it on a Server machine as well with all software firewalls and anti-virus disabled. I am using voip-unlimited as a sip provider and calls to and from my 3CX phone system keep dropping after 30 seconds exactly with ACK not receieved.
