In an office, it is reported that the common voice services of an MA5606T are normal; however, the IPT service of the MA5606T fails. After the number is dialed, the system prompts "the number you dial does not exist."
1. The IPT call flow is as follows: After a user picks up the phone, the phone automatically reports the access code 200. After receiving the access code, the softswitch requires the MA5606T to set up a connection with the media resource server. The media resource server then plays the dial tone for the user through the media stream, and the user dials the number also through the media steam. After that, the media resource server modifies the context, and then MA5606T sets up a connection with the peer media gateway.
2. Log in to the MA5606T through telnet, and use the DBWin to trace the signaling. It is found that the MA5606T reports the access code 200 about 10 seconds after the dial tone is delivered. The on-site operation is that the number is dialed immediately the dial tone is heard. We can see that the user mistakes the dial tone played by the DSP chip of the MA5606T for the dial tone played by the media resource server when the softswitch issues the signal cg/dt. This causes the user to dial the number within the 10 seconds. The access code 200, however, is reported after the 10 seconds expire.
3. The solution is to let the access code be reported immediately the phone is picked up so that the user can hear the dial tone played by the media resource server through the media stream instead of the dial tone played by the DSP chip. Check the signaling, and it is found that no 200 exists in the digitmap. Instead, the access code is matched to the X.L at the end of the digitmap. The following shows the digitmap.
The duration of the long timer is 10s, resulting in the reporting of access code 200 after the 10 seconds expire.
4. Make the digitmap be added with 2XX. Then, the access code 200 is reported immediately the phone is picked up. Perform the dialing test on site. It is found that the fault is rectified.