Yes Mitch, I did that but the Fax internal messages are printed by this line which has no knowledge of the session. switch_log_printf(SWITCH_CHANNEL_LOG, fs_log_level, "%s", msg); I do not think, it can print the uuid without knowing the session ? Here is a log snippet to show uuid prefixed at other places except line 286 of mod_spandsp_fax.c shown above 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 1... ....= Extension indicator: Set 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 .... ..0.= Compressed/uncompressed mode: Compressed 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 .... .1..= Error correction mode (ECM): ECM 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 .... 0...= Frame size: 256 octets 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 .1.. ....= T.6 coding: Set 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 0... ....= Extension indicator: Not set 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:286 FLOW T.30 Selected compression T.6 (3) 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:327 === Negotiation Result ======================================================= 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:328 Remote station id: 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:329 Local station id: Sangoma Fax Ident 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:330 Transfer Rate: 4800 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:332 ECM status on 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:333 remote country: 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:334 remote vendor: 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:335 remote model: 46736448-77e4-11e1-855c-b3286880c45b 2012-03-27 13:40:38.604877 [DEBUG] mod_spandsp_fax.c:337 ========================================================================= regards, Anita