ZyXEL Communications P-2302R-P1 - Manual (Page 112)

P2302R-P1 Support Notes
All contents Copyright

2007 ZyXEL Communications Corporation.
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inside and you want users to be able to use things such as www.yourhost.dyndns.org and still reach your
hostname.
Does the ZyXEL Device support DDNS wildcard?
Yes, the ZyXEL Device supports DDNS wildcard that WWW.DynDNS.ORG supports. When using wildcard,
you simply enter yourhost.dyndns.org in the Host field in Menu 1.1.
Can the ZyXEL Device SUA handle IPsec packets sent by the VPN gateway behind ZyXEL
Device?
Yes, the ZyXEL Device's SUA can handle IPsec ESP Tunneling mode. We know when packets go through
SUA, SUA will change the source IP address and source port for the host. To pass IPsec packets, SUA must
understand the ESP packet with protocol number 50, replace the source IP address of the IPsec gateway to the
router's WAN IP address. However, SUA should not change the source port of the UDP packets which are used
for key managements. Because the remote gateway checks this source port during connections, the port thus is
not allowed to be changed.
How do I setup my ZyXEL Device for routing IPsec packets over SUA?
For outgoing IPsec tunnels, no extra setting is required. For forwarding the inbound IPsec ESP tunnel, A
'Default' server set in menu 15 is required. It is because SUA makes your LAN appear as a single machine to
the outside world. LAN users are invisible to outside users. So, to make an internal server for outside access, we
must specify the service port and the LAN IP of this server in Menu 15. Thus SUA is able to forward the
incoming packets to the requested service behind SUA and the outside users access the server using the ZyXEL
Device's WAN IP address. So, we have to configure the internal IPsec as a default server (unspecified service
port) in menu 15 when it acts a server gateway.
VoIP FAQ
What is Voice over IP?
Voice over IP is an emerging technology based on open standards of IEEE, fundamentally the Internet Protocol,
that allows voice data to travel across the Internet. There are many method to used this technology, the most
common and well known are SIP, and H.323.