SIP Call does not work
Introduction
MOBOTIX cameras support the SIP protocol to make calls as Actions in case of Events or as Time Tasks. It is also commonly used in combination with the Door Station to route calls when someone presses the Bell Buttons.
A MOBOTIX camera can act both as a SIP server and as a SIP client. As a server the camera is a full fledged PBX where SIP clients can be registered. As a client the camera connects to an external SIP server and can be used to call the different extensions.
How to test a call
Step 1. Go to Admin Menu > Outgoing Calls Settings
Step 2. Select the test profile name from the drop-down menu and click the Test button. The client should receive the call.
If the call works as a test but it does not work as an action
In this case it could be that Parallel Dialing is Enabled in the Admin Menu > SIP Client Settings.
Parallel Dialing is an option that can be used when the MOBOTIX camera acts as a SIP Server to notify multiple extensions simultaneously. In order to achieve that, a different source port is used for each extension that has to be notified.
NOTE: Although the notification is sent to multiple extensions, only the first one that accepts the call will be able to establish a audio/video connection with the camera. If the goal is to establish a communication with multiple clients it’s possible to leverage the RTP Pager functionality available under Admin Menu > RTP Pager (only on Mx6 series with firmware 5.0.2.13 or greater).
If the camera is registered as a SIP Client on an external SIP Server, Parallel Dialing might prevent the call from being placed. In fact, when using external SIP servers that are checking the source ports of the call requests against the source ports of the registration, this feature cannot be used as the ports will differ from the registered ones.
Disable Parallel Dialing to overcome the problem but please be aware that only one extension at a time can be notified.
If multiple extensions shall be notified simultaneously, it will be sufficient to create a hunt group on the external PBX and have the camera call the extension of the hunt group.
If the call does not work as a Test
In this case there are multiple possibilities.
- Verify the Network Settings, enable the Gateway and DNS.
- Verify the User Credentials both as a SIP Server and as a SIP Client
- Verify the User Credentials on the SIP Clients connected to the camera working as a SIP Server
- Go to Admin Menu > SIP Client Settings and at the top of the page click on SIP Client: Messages, Calls, Status. In the Status section the camera displays its status as a client connected to iself as a Server or to any external SIP Server. It must show the status Connected
- Verify the SIP Clients, most of them have logs or On-Screen status messages that display error messages in case of failure to login.
Finally if all these steps have been verified run a network trace on the camera. If the camera is a client on an external SIP Server and it registers but it does not route the call then more network traces are necessary to properly analyze a case:
- Network trace on the camera while trying to call
- Network trace on the SIP client receiving or sending the call
- Network trace on the PBX routing the call between the SIP client and the camera
Conclusion
SIP is a complex communications protocol which works in conjunction with several other protocols that specify the media format and coding and that carry the media once the call is set up. The camera acts both as a client and as a server.
Analyzing connectivity issues can be complicated when third party products are involved as the camera is only a part of the ecosystem. When an external PBX is used or complex network configurations are in place it is recommended that the installation and troubleshooting is carried out by a certified network and PBX technician.