Napt And Ppp & Ip Routing - Alcatel Speed Touch Wireless User Manual

8 Data Services - PPP & IP Routing
8.4.6 NAPT and PPP & IP Routing
NAPT
NAPT and supported
protocols
Configuration of NAPT
NAT/PAT and
STWireless
transparency
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Network Address Translation (NAT) is a technique that allows you
to shield or decouple an internal (Private) IP address from the
(negotiated) external (Public) IP address.
In addition, via Port Translation (PT), this single external Public IP
address is mapped onto multiple internal ports on the (W)LAN,
thus allowing multiple users to share this external IP address
simultaneously.
The amalgam of address & port allocation is often referred to as
NAPT.
All supported protocols that are NAPT insensitive, pass
transparently through NAPT.
In addition, the STWireless supports also the following protocols
as NAPT insensitive:
All generic TCP/UDP protocols, e.g. HTTP (Hyper Text Transfer
"
Protocol)
Internet Control Message Protocol (ICMP)
"
File Transfer Protocol (FTP)
"
Internet Relay Chat (IRC)
"
Real Audio
"
Real Time Stream Protocol (RTSP).
"
You can enable/disable NAPT via the 'PPP Configuration' web
page per PPP entry.
In the 'Routing' box (See subsection 8.4.4) it is possible to
set/unset the NAT flag (n).
Advanced NAPT can be configured via the CLI. See chapter 19 for
more information.
The NAPT feature comes at the expense of the STWireless
transparency. For consequences and solutions, see subsection
8.4.7.
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