Ericsson W3X User Manual

Page 54

Configuration and Management

1/1551-CRH 102 168 Uen Rev A 2008-12-16

3.7.1 UPnP

IGD

The Ericsson W3x supports the Universal Plug and Play (UPnP) Internet
Gateway Device (IGD) standard. UPnP IGD is used to provide automatic
port forwarding allowing communication between certain Internet
applications and the local network. When UPnP IGD is enabled, programs
like MSN Messenger

and most network enabled games are allowed to

pass the NAT service.

UPnP IGD is enabled by default, but if you want to disable the feature, clear
the “Enable UPnP IGD” check box and click

Apply

to save the settings.

3.7.2

Application Level Gateways

From a security perspective, certain Internet applications, for example FTP
applications that open additional ports upon transfer, are especially
problematic to handle. An Application Level Gateway (ALG) provides a
translation and transportation service for such a specific application.
Incoming data packets are checked against existing NAT and packet
filtering rules, IP addresses are evaluated and a detailed packet analysis is
performed. If necessary, the contents of a packet are modified and if a
secondary port is required, the ALG will open one. The Ericsson W3x
includes ALG support for the following applications:

Table 17 - ALG Supported Applications

Application Protocol

Port
number

File Transfer Protocol (FTP)

TCP

Trivial File Transfer Protocol (TFTP)

UDP

Point-to-Point Tunneling Protocol (PPTP)

TCP/UDP

1723

Session Initiation Protocol (SIP)

TCP/UDP

5060

Real Time Streaming Protocol (RTSP)

TCP/UDP

554

The ALG for each application does not require additional configuration. The
supported ALGs can be enabled and disabled individually.

To disable an ALG, clear the corresponding check box and click

Apply

save the settings.