Confused of London, again: With the following configuration, E1<------------------------------->PRI Card #1 Meridian PBX (Clock controller enabled) E1<--->Span1-TE405P on *-Span2<--->PRI Card #2 Meridian PBX (CC disabled), What should the timings be ? Currently I have timing on Span 1. This is my zaptel.conf # # Zaptel Configuration File # # This file is parsed by the Zaptel Configurator, ztcfg span=1,1,0,ccs,hdb3,crc4 bchan=1-15,17-31 dchan=16 span=2,0,0,ccs,hdb3,crc4 bchan=32-46,48-62 dchan=47 loadzone = uk defaultzone=uk With the following configuration, E1<--->Span1-TE405P on *-Span2<--->PRI Card #1 Meridian PBX (CC enabled), E1<--->Span3-TE405P on *-Span4<--->PRI Card #2 Meridian PBX (CC disabled), What should the timings be ? Any help is much appreciated. Julian