SIP not register from second network in vpn

Hi,
i’ve many pbx with freepbx 4.211.64-6. I use firewall USG 20 with site to site vpn and l2tp vpn.
In all installation i haven’t problem with phone that are in different network class connected in vpn.
In the last installation i can’t register the hardware and software phone:
site A where there is freepbx virtualized with vmware 4: 172.17.1.0/24
site B : 172.17.10.0/24
remote from l2tp: 192.168.86.15 - 192.168.86.20
Vpn are created with an zyxel USG 50.
I can ping from any site to pbx 172.17.1.209
I can ping from pbx any ip in any site and l2tp.
The local site A phone can register and call and receive.
The remote hardware and software phone can’t register.
Asterisk received the SIP request, but i think the response is not send to telephone. Can be a vpn issue?
This is the debug:

<— SIP read from UDP:172.17.1.200:5060 —>
REGISTER sip:172.17.1.209:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.86.15:5060;branch=z9hG4bK-d8754z-fb3b8b49a3706635-1—d8754z-;rport
Max-Forwards: 70
Contact: sip:[email protected]:5060;rinstance=c29e08a6ddc37aaa
To: "209"sip:[email protected]:5060
From: "209"sip:[email protected]:5060;tag=75243d2f
Call-ID: MWRmZDc4NmIyNDhiOGMzZGI0MWVlMWE4NTcwYWNmMzg.
CSeq: 1 REGISTER
Expires: 120
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE
Supported: replaces
User-Agent: 3CXPhone 6.0.26523.0
Content-Length: 0

<------------->
[2013-09-12 21:06:17] VERBOSE[2089] chan_sip.c: — (13 headers 0 lines) —
[2013-09-12 21:06:17] VERBOSE[2089] chan_sip.c: Sending to 172.17.1.200:5060 (no NAT)
[2013-09-12 21:06:17] VERBOSE[2089] chan_sip.c:
<— Transmitting (no NAT) to 172.17.1.200:5060 —>
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 192.168.86.15:5060;branch=z9hG4bK-d8754z-fb3b8b49a3706635-1—d8754z-;received=172.17.1.200;rport=5060
From: "209"sip:[email protected]:5060;tag=75243d2f
To: "209"sip:[email protected]:5060;tag=as326e4a66
Call-ID: MWRmZDc4NmIyNDhiOGMzZGI0MWVlMWE4NTcwYWNmMzg.
CSeq: 1 REGISTER
Server: FPBX-2.11.0(11.4.0)
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH
Supported: replaces, timer
WWW-Authenticate: Digest algorithm=MD5, realm=“asterisk”, nonce="0ff863ab"
Content-Length: 0

Can you help me?

Did you add that network to localnet table in sip settings module?

yes. I’ve add the network localnet in sip settings of freepbx.
The firewall have alg disable.
Now have increase udp time-out in firewall settings.
But the problem not change. PBX receive the invite but the phone not receive the response.

Thank you.

Do you have NAT turned on in the tunnel? What happens if you traceroute from the Asterisk box to the remote SIP endpoint?