Apologies for a simple newbie question.  Following examples in the first two FreeSWITCH books, have been able to set up a SIP gateway, register, and receive calls.
However I can't make calls.  The dialplan is being entered, but 'hangs' at

switch_channel.c:1055 New Channel sofia/external/16475551212

a)  The provider name is "babytel".
b)  The dial plan bridge is to data="sofia/gateway/babytel/$1"  (as per the books)
c)  The provider xml file is in conf/sip_profiles/external  (as per the books)

d)  sofia status
Name:  external::babytel
Type:  gateway
State:  REGED

Why is the bridge channel called "sofia/external/...."?  And not "sofia/babytel/..."?   
Why does sofia status show "external::<provider>" (the books just show the provider name)?

Can anyone explain why the bridge to the gateway does not occur?

Thank you,
Ian.