asterisk users - Mar 2005 - Could dialing long extensions be a problem?

I have two DIDs from NuFone.
I have for the first DID a short extension (601 = 3 digits) and on the 
other one a long extension (886212345678 =12 digits)

Extensions.conf looks like:


[fromNuFone]
exten => 888xxxxxxx,1,Dial(SIP/601,20,tr)
exten => 888xxxxxxx,2,Dial(SIP/602,20,tr)
exten => 888xxxxxxx,3,hangup
;
;
exten => 866xxxxxxx,1,Dial(SIP/886212345678,60,tr)
exten => 866xxxxxxx,2,Voicemail,u886212345678   
exten => 866xxxxxxx,103,Voicemail,b886212345678
exten => 866xxxxxxx,104,hangup

first one works, second one not!!!!

*CLI shows:

    -- Executing Dial("IAX2/NuFone@198.22.67.70:4569-18", 
"SIP/601|20|tr") in new stack
    -- Called 601
    -- SIP/601-de44 is ringing
...
    -- Executing Dial("IAX2/NuFone@198.22.67.70:4569-10", 
"SIP/886212345678|60|tr") in new stack
Mar  9 09:31:38 WARNING[29209]: chan_sip.c:1405 create_addr: No such 
host: 886212345678
Mar  9 09:31:38 NOTICE[29209]: app_dial.c:927 dial_exec_full: Unable to 
create channel of type 'SIP' (cause 3)

changing to a short extension works!



However, dialing from 601 to 886212345678

[long_extensions]
exten => 886212345678,1,Dial(SIP/886212345678,60,tr)
exten => 886212345678,2,NoOp(${DIALSTATUS})
exten => 886212345678,3,Voicemail,u886212345678  
exten => 886212345678,104,Voicemail,b886212345678
exten => 886212345678,105,hangup


   -- Executing Dial("SIP/615-610d",
"SIP/886212345678|60|tr") in new stack
    -- Called 886212345678
    -- SIP/886212345678-e925 is ringing


How can I solve it?


bye

Ronald