We are using your company’s product, Cisco UC560.
We are using sip trunk to call in and out.
But now we have some problems.
When we use it to call out, we don’t have any question.
When client phoned into our company, the dial tone was keep on sounds like “DO DO DO”.
Moreover, the other side, our company, the phone was ring.
However when we pick up the phone, there was no sound.