i have router equiped with 6 E1. 3 for PSTN and other 3 E1 trunk QSIG with othe othe vendor PBX. Cisco is the gateway for the pbx users to call out. we are facing an issue in high traffic hours call get error tone or busy tone when trying to call from the pbx user. in normal times calls get through without any porblem. anyway i suspect in synrchronization issue.
how should i programm the PRI clock source and synchronization for each of them? for the PSTN side and also for the E1 Qsig side?