Prestige 2302RL Support Notes
All contents copyright (c) 2007 ZyXEL Communications Corporation.
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Can VPN tunnels still work on a Prestige using SUA?
Yes, the Prestige's SUA still works in IPsec ESP Tunneling mode. When packets go through the Prestige, SUA
will translate the source IP address and source port for the host. To forward IPsec packets, the Prestige SUA can
identify ESP packets with a protocol number of 50. Thus SUA will replace the source IP address of the IPsec
packet with the router's WAN IP address. However, SUA will not change the source port of the UDP packets
which are used for key managements. Since the remote gateway checks the actual source port during connection
negotiation, SUA should not change the original source port.
How do I set up my Prestige to route IPsec packets over SUA?
For outgoing IPsec tunnels, no extra setting is required. To forward packets through the inbound IPsec ESP
tunnel, you must configure the 'Default' server set in SMT menu 15. It is because SUA makes your LAN appear
as a single device to the outside world. LAN users are invisible to outside users. So, to make an internal server
accessible from the outside, you must specify the service port and the LAN IP address of the internal server in
SMT menu 15. Thus Prestige is able to forward incoming packets to the requested service behind SUA and the
outside users can access the server using the Prestige's WAN IP address. You must configure the internal IPSec
gateway as the default server (unspecified service port) in SMT menu 15.
VoIP FAQ
What is Voice over IP?
Voice over IP (VoIP) is an emerging technology based on the open IEEE standards. VoIP refers to the
transmission of voice data over the Internet. Various protocols are available for voice transport. The most
commonly used are SIP and H.323.
Voice over IP (VoIP) is an emerging technology based on open IEEE standards. VoIP refers to the transmission
of voice data over the Internet. Various protocols are available for voice transport. The most commonly used are
SIP and H.323.
How does Voice over IP work?
In VoIP, voice data is sent digitally in discrete packets through the Internet, not through the traditional circuit
switch of PSTN. To do so, an analog-to-digital converter is required at sender side to translate voice (analog
signal) to digital signal before transmission. At the receiver end, an analog-to-digital converter converts the
digital signal back to analog so the voice can be heard on the phone.