{"wiki":"en","slug":"problem-rufausloesung","markdown":"\n\n# Calls cannot be established\n\nIt may not be possible to trigger calls on the Behnke Station even though it is successfully registered on your SIP server or your PBX. This can have different causes.\n\n## 1. Problem with the button\n\nThere may simply be a problem with the call button. To rule out the call button as a source of error, please proceed as described in the following trouble shooting guide: [Pressing a button without effect](Problem_Tastendruck)\n\n## 2. Problem establishing a call via SIP\n\nWhen setting up a call, various parameters are negotiated via SIP, such as the codecs used or the port numbers used for the audio streams. It's possible that this negotiation fails for various reasons and therefore the call cannot be established. As a test, you can enable the option **\"late offer / SDP in ACK\"** in the Behnke Station's SIP settings in **\"Media management\"**. Under certain circumstances this may improve the situation and resolve the problem:\n\n\n\nIf this is not the case, or if you notice other problems after chenging the setting, please set the **\"Media management\"** back to **\"early offer / SDP in INVITE\"**.\n\n## 3. Other problems\n\nFailing call establishing is often not related to the Behnke Station itself, but rather to the settings of the telecommunications system, the remote station, or the configuration of the network. Below is a list of common causes not directly related to the Behnke Station:\n\n- License problems with the PBX (not enough free licenses available, licenses have expired, etc.)\n- Incorrectly set up call diversions/forwarding\n- Behnke Station does not have the authorization to initiate calls or for direct outward dialing\n- SIP proxy cannot be reached from the Behnke Station (e.g. firewall problems, routing problems, VLANs, etc.)\n- Behnke Station's IP address is blacklisted by the PBX\n- Behnke Station is set up in the PBX as a “intercom” and not as a SIP device\n\n## 4. Generating diagnostics\n\nIf you can rule out the above sources of error, please save the Behnke Station's diagnostics and create a support ticket using the form.\n\nYou can download the diagnostics via the menu item **\"Diagnostics\"**. Simply click on the 'download' button in the **\"Log\"** section and save the zip file.\n\n\n\nYou can get to the support ticket form via the following link: .\n\n## 5. Legal notices\n\n[Legal notices](legal notices)","lastModified":"2026-08-20T14:30:11+02:00"}