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when i place a call, after one beep (about one second) the T48G shows me a error message: Service unavailable and it gives me a busy tone.

If the other person, i call, takes the call directly, i can speak with him.
But if not, it is not possible to establish the call.

Thanks for help,

thanks for your information

for your issue, do you mean the scenario like below :

1. A and B all register to the same PBX
2. A call B, after A dial the number of B and then hear a ring back beep , then the LCD of A will show "Service unavailable" and it gives me a busy tone.
3. but if A call B, B answer the call within the time A receive the ring back beep , then A and B can establish a call successfully

please point out if any misunderstanding and then check the below items :

1. upgrade the T48 to the last firmware ,firmware download link :

2. reset to factory and test again

if all the above solution can't solve your issue, please provide us the trace file for future analysis,trace file including pcap file, config bin and syslog file , and we need three of them provide at one time.

for how to get them , please refer to the FAQ below:

do the above test and send all the trace files to

6 files totally,
3 files (bin ,syslog,pcap ) when call showing "Service unavailable"
3 files (bin ,syslog,pcap ) when call establish

let me know if any question


I have the same Problem. Firmware is The phone is connected to a bintec be.IP plus.

Status changed: Downgrade to Firmware solved the problem.
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