I'm having a problem with my Elastix 1.4-4 system. I have a couple SIP devices and a Nortel i2004 using chan_unistim. I can not dial the unistim device from any SIP device, but dialing from the Nortel i2004 to a SIP phone works fine. I get the following errors in my asterisk log when I try to call the Nortel phone. 3602- Sip phone 3605- Unistim Nortel i2004 Mar 28 16:53:57 VERBOSE  logger.c: -- Executing [s@macro-dial:7] Dial("SIP/3602-09b27c40", "3605,1,Macro(stdexten,3605,USTM/3605@afmi2004)||tr") in new stack Mar 28 16:53:57 NOTICE  app_dial.c: Hey! chan SIP/3602-09b27c40's context='macro-dial', and exten='s' Mar 28 16:53:57 WARNING  channel.c: No channel type registered for '3605,1,Macro(stdexten,3605,USTM' Mar 28 16:53:57 WARNING  app_dial.c: Unable to create channel of type '3605,1,Macro(stdexten,3605,USTM' (cause 66 - Channel not implemented) Mar 28 16:53:57 VERBOSE  logger.c: == Everyone is busy/congested at this time (1:0/0/1) I've created a custom extension in Elastix with the following dial string: 3605,1,Macro(stdexten,3605,USTM/3605@afmi2004) and here is my unistim.conf [afmi2004] device=006038764e29 context=from-internal mailbox=3605 linelabel="Bar" line => 3605 bookmark=Mailbox@*97@54 Thanks for any help!