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

8 PPP & IP Routing
8.5.5 NAPT and PPP & IP Routing
NAPT
NAPT and supported
protocols
Configuration of NAPT
NAT/PAT and STPro
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 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
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 figure 46) it is possible to set/unset the
NAT flag (n).
The NAPT feature comes at the expense of the
transparency. For consequences and solutions, see subsection
8.5.6.
supports also the following protocols as
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