Hi, we have v10spk1 running on XP spk3 and some Cisco phone (SPA 502g and 504g - using P.O.E switch) and 'SOME' users are claiming regarding echo during external calls (outbound/inbound via sip trunk or via gateway - SPA400). How can I debug this issue? It would be related with network latency? Codec used in the phones? * I´m monitoring right now through SNMP my ADSL modem connection, 3cx server and so on.