Hi, I am trying to track down the reason to my problems with sending and reciving fax with my PRI and 2 TDM400P Cards: PSTN <-> PRI (E100P) <-> * <-> TDM400P <-> Fax Machine I have used Zapbarge to listen to the data stream, but I can't say if it really have some time slips - fax kinda noisy in itself. Using the zttool i saw the Sync source for the TDM are "internally" - what does that mean? Are they using an "on-board" source, or using the PRI (which is configured to use the telco as sync source). The zttool reports this for the E100P: Sync Source: Digium Wildcard E100P E1/PRA C For the TDM400P cards it reports : Sync Source: Internally clocked Is there a way to specify which source the TDM cards should use? Div system info: System: SuperMicro with P4 2.53GHz 512 MB Ram 3Ware IDE Raid Cont. (Running Raid 5) 1 x E100P 2 x TDM400 Kernel-2.6.8.1 (No ACPI) Asterisk, Libpri and zaptel is from stable 1.0.2 release zaptel.conf span=1,1,0,ccs,hdb3,crc4 bchan=1-15,17-31 dchan=16 fxoks=32,33,36-39 fxsks=34,35 cat /proc/interrupts CPU0 0: 954710104 XT-PIC timer 1: 20 XT-PIC i8042 2: 0 XT-PIC cascade 5: 954609651 XT-PIC wctdm 7: 954739525 XT-PIC wctdm 10: 2858318 XT-PIC eth1 11: 32640181 XT-PIC eth0 12: 214 XT-PIC i8042 14: 954602423 XT-PIC t1xxp 15: 5550321 XT-PIC 3ware Storage Controller NMI: 0 LOC: 954781513 ERR: 0 MIS: 0 -- Med venlig hilsen / Best regards Michael L?jtnant - Systems Engineer ZyXEL Communications A/S Columbusvej 5 - 2860 S?borg Tel (+45) 3955 0700 - Fax (+45) 3955 0707