I have some problems about the IP COM system.1.when a call had finished, a few minutes later I made another call, but i could not hear any dial tone. After that, showing command in IAD 2430 (connect directly to telephone via FXS port), I found that t...

when the phone off hook,some time no dial tone and when conversation,the call drop.We use cisco iad 2430 to connect phone or pbx.Please help me.Sorry about my English not good