When I try to connect from PTT dispatcher, I get the following message in Asterisk: Connected to Asterisk 1.4.28 currently running on localhost (pid = 1596) [Feb 1 18:49:55] NOTICE[1609]: chan_iax2.c:9421 socket_process: Host 77.99.120.109 failed to authenticate as gui The iax config file for gui is: ; for all iax2 connections allow=ulaw allow=alaw allow=gsm jitterbuffer=yes tos=lowdelay ; for app_rpt connections [radio] type=user disallow=all allow=g726aal2 allow=gsm codecpriority=host context=radio-secure ; for iaxRpt client connections [gui] type=user disallow=all allow=ulaw allow=gsm context=radio-gui auth=md5 secret=password host=dynamic transfer=no The username/password have been doubt checked in ptt dispatcher. Any suggestions on where else to look, e.g. less obvious causes if this error? Regards Nathan