We have recently installed an Asterisk system in an external facility. It manages around 100 public telephones, these telephones use several Gateways FXS when they performe voice calls (using a VoIP Provider), and one Gateway FXO in order to dial the number of a modem and send statistics every day (there are no inbound calls).
The voice communications work ok, but I’m having problems with the data communications. Everytime the Gateway FXO tries to communicate with the modem, I receive a “Hangupcause:19 - NO_ANSWER” or a “Hangupcause:34 - NORMAL_CIRCUIT_CONGESTION” error message (it takes 30 seconds until the call is dropped).
This is not the first time that we install this kind of system, so in theory everything should be well configured. ¿Any leads about what may cause the issue?