PSTN phone A------MA5616-------CS2000------Unknown------PSTN Network-----Phone B
MA5616 version: V800R307C00SPC200
Softswitch of the N company: CS2000 CVM12 RELEASE
In the preceding networking mode, if A acts as the caller and B acts as the callee, after A dials the number of B, A hears the busy tone and B does not ring. If A acts as the callee and B acts as the caller, after B dials the number of A, A rings once and B hears the busy tone.
The fault symptom is the same regardless of whether phone B is a handset or a phone set in common PSTN.
1. First, check the ringing mode and the CLIP function.
The following dialing mode and caller ID display parameters are displayed in the signaling delivered by the softswitch: ddb=801601083131323631333532020A34393536303931313135B7,pattern=1
To simplify problem handling, ask the customer to disable the caller ID display function first. After this function is disabled, the fault persists. Because the softswitch delivers the pattern=1 ringing mode, this mode is configured on the MA5616. The fault, however, persists.
2. Check signaling exchange. No error information replied by the softswitch or MA5616 to the peer is found.
3. Analysis grapples with difficulties. The customer provides the signaling of successful interoperation between the AG and CS2000 of the K company to us for comparison and analysis.
4. Upon the comparison between the signaling of our device and the AG signaling of the K company provided by a customer, a little abnormality is found, that is, the signaling replied by the MA5616 to the softswitch carries a remote descriptor, but the Keymile does not carry the remote descriptor. According to the analysis in the early stage, the CS2000 delivers the subtract message immediately after the MA5616 responds with the remote descriptor. Thus, the fault may be caused by the remote descriptor.
5. Modify the H248 profile on the MA5616, so that the remote descriptor is not replied. Perform the test again. It is found that the fault is rectified and the caller and the callee can communicate with each other normally. Therefore, the cause of the fault is that after the CS2000 receives a reply with the remote descriptor from the MA5616, the CS2000 considers the reply to be illegal and releases the call immediately.
For the screen snapshot, that is, the detailed analysis of relevant signaling, see the attachment.
1. One ringing tone may be related to the ringing mode and the CLIP function.
2. Signaling exchange is abnormal.
In the case of interoperating with the softswitch of the N company, because the types of provisioned services vary with regions, profile 0 is recommended. Using profile 0, users can flexibly set the value of each parameter.