I want to connect Cisco CM 6.0 to Siemens HiPath 4000 Release 3.0 using a SIP trunk. The Siemens HiPath got a built-in SIP trunk module and authentication is done on IP basis.
There is no problem when we are calling from Cisco to Siemens. But when calling from Siemens to Cisco, the Cisco CallManager gives a http 400 bad-request back. Maybe this is caused due to a misconfiguration on either Cisco or Siemens side.
Did someone configure Cisco CM 6.0 and Siemens HiPath 4000 using SIP trunk module? Any help will be highly appreciated.