Where and how to specify the current external ip address for the telephony provider?

Question

Asterisk

How to do it? :(
costs elastix + asterisk

If you connect a SIP-PBX or your equipment works on an external ip-address, then use the sip.xxx.com:5068 server instead of the voice.xxx.com:5068 server. Your equipment (SIP-PBX) in this case should indicate your current external IP address in SIP packets.

I tried a bunch of options: externhost=external ip, externip=external ip.
Anyway, the provider for some reason sees my local IP address, which knocks on their servers. But the fact is that for security, the provider has made a binding to my external ip address, as a result, I can’t get normal registration.
It's not about the server, because other lines that do not have an IP binding are registered normally.
They still see my local IP. in sip_general_custom.conf I registered my external address externaddr=xxx
Here is my trunk config:
[telphin1]
username=xxx
type=peer
secret=xxx
registersip=yes
qualify=yes
promiscredir=yes
port=5060
nat=route
insecure=port,invite
host=sip.telphin.com
fromuser=xxx
fromdomain=ip
dtmfmode=rfc2833
allow=alaw
allow=ulaw
context=from-trunk-sip-telphin1
Here is the actual error:
[2015-08-11 06:14: 10] NOTICE[3675]: chan_sip.c:15067 sip_reg_timeout: -- Registration for '[email protected]' timed out, trying again (Attempt #12)
Telphin says the problem is they can see my local address , but must external.
Everything is wrong with the line, on the asterisk this line is registered normally, but in a freshly installed elasticix - no.

Answer 1

externip= must be added to sip.conf
in case of elastix in sip_general_custom.conf

Answer 2

for security, a binding was made to my external ip address

if the IP is dynamic, then this is a stupid idea

Answer 3

As I understand it, your PBX is behind NAT. Specify your external IP on the PBX.