[Asterisk-Users] newbie: help two cisco phones (sip)

[Andrew White]

Hi,

I have two cisco phones with sip images and I am trying to configure
to work with asterisk.  Both can call demo numbers and voicemail etc. 
but can't call each other.

sip show registry and sip show users both indicate that asterisk
doesn't know the phones ip addresses,  and when u try to place a call,
 it forwards to unanswered voicemail immediately.

I have tried user_info: ip  and also phone, but can't seem to get the
phones to register.

sip.conf  has host=dynamic for both phones

SIP image is version 7

anyone able to tell me where i'm going wrong ?

tks

Andrew