We have a UC540 set up in the office, registered with the ITSP for SIP and can make calls quite happily, out over the SIP trunks. When I call in to the SIP number however, all I receive back is busy tone. The call is being delivered to the Public IP address of the network the UC 540 is connected to, but is being rejected by the UC540 with the error:
400 Bad Request - 'Invalid Host'
Where on CCA can I fix this issue please? Any and all help gratefully received.
It is probably a simple solution such as adding in your ITSP IP address into the allowed list, when enabling SIP on the system that ACL's start to lock the box down to protect it from Toll fraud a little more agressivley than if you were not using SIP, it also has other peripheral settings such as SOURCE lists and what not.
If you contact the ITSP and ask them for a list of IP addresses that they may use for either fail over, load balancing or for any other reason, you would then log into CCA and go into your SIP Trunk drawer and add them into your trusted list, this should open up the system to all inbound requests and should fix it up.
If the above does not work then there might be a more deep seeded issue that needs to be looked at.