I have one SPA3102 with its FXS connected to a PBX and FXO to POTS. If I send one fax from PBX side the call seems connect with remote side but after some secons the operation fails. Outgoing fax are sent from FXS to FXO directly via dialplan. All works ok without connect SPA. Must I change any param from standard params? It has CED and CNG detection on. I am from Spain.