Alcatel AST570, User Manual

Page: 206 / 300

Use of NA(P)T
NA(P)T and supported
protocols
16 Security Services - NAT & PAT
206 / 300
3EC 17766 AAAA TCZZA Ed. 04
16.1 Speed Touch and NA(P)T
NAT is a technique used to share one IP address amongst several
PCs. For most applications, enabling NA(P)T on a specific AST570
interface, e.g. the Routed Ethernet interface is adequate. From
then on, all Routed Ethernet clients behind the AST570 NAPT
router automatically share the same IP address.
To serve that purpose, on all relevant
AST570 pages a NAT
checkbox can be found.
The use of these checkboxes is described in section 16.2.
However, to run one or several servers behind a NAPT router,
additional configuration is needed. Therefore, the AST570
exhibits the 'NAT' page, allowing static IP address and UDP/TCP
port mapping for inbound IP packets to be configured.
The use of the
'NAT' page is described in section 16.3.
All supported protocols that are insensitive for NA(P)T, pass
transparently through the AST570 NA(P)T router.
In addition, the AST570 supports also the following protocols as
NA(P)T insensitive:
All generic TCP/User Datagram Protocol (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).
To allow the multimedia protocols defined in the H.323 and
H.245 ITU recommendation to be transparent for the AST570
NA(P)T router, e.g. for using Netmeeting over the DSL line, the
AST570 exhibits specific protocolhelper applications for:
H.323
H.245.