X-lite error 404

Hello.
This he is my first post and my first experiences with asterisk.
It is that I have installed TRIXBOX 1,2 and I have formed 2 extensions to prove to make a call from an equipment to another one of my network with x-lite.

The case is that it gives east error me: Registration error 404 - Not found

To that it can have? Some idea?
I take to 3 days looking for information on the subject and nonencounter nothing.

sip.conf

; Note: If your SIP devices are behind a NAT and your Asterisk
; server isn’t, try adding “nat=1” to each peer definition to
; solve translation problems.

[general]

port = 5060 ; Port to bind to (SIP is 5060)
bindaddr = 0.0.0.0 ; Address to bind to (all addresses on machine)
localnet=10.0.0.0/255.255.255.0 ; nuestro rango de red interna
externip = 10.0.0.7 ; nuestra ip p?blica
language=es ; idioma

disallow=all
allow=ulaw
allow=alaw
; If you need to answer unauthenticated calls, you should change this
; next line to ‘from-trunk’, rather than ‘from-sip-external’.
; You’ll know this is happening if when you call in you get a message
; saying "The number you have dialed is not in service. Please check the
; number and try again."
context = from-sip-external ; Send unknown SIP callers to this context
callerid = Unknown
tos=0x68

; #, in this configuration file, is NOT A COMMENT. This is exactly
; how it should be.
#include sip_nat.conf
#include sip_custom.conf
#include sip_additional.conf

Parametros X-Lite

en SIP Acount
User name: 111
Password: 111
Domain: 10.0.0.7
Domain Proxy:
proxy: 10.0.0.7:5060

The servant where I have installed it has an IP of 10.0.0.7 and attempt to accede from another PC connected with hub with he himself rank of IP.
When trying to connect with x-lite puts the error to me 404 that commented.
In addition I have been created 2 extensions, the 111 and the 222 (that original) with the equal passwords that the accounts.
Some idea or helps?
(it is what has this of being inexperienced! )
Thousand thanks.