ZyXEL Communications ADSL2+4 Benutzerhandbuch

 Chapter 8 Network Address Translation (NAT)

P-660H-T1v3s User’s Guide

Some NAT routers may include a SIP Application Layer Gateway (ALG). A SIP ALG 
allows SIP calls to pass through NAT by examining and translating IP addresses 
embedded in the data stream. When the P-660H-T1v3s registers with the SIP 
register server, the SIP ALG translates the P-660H-T1v3s’s private IP address 
inside the SIP data stream to a public IP address. You do not need to use STUN or 
an outbound proxy if your P-660H-T1v3s is behind a SIP ALG.

Use this screen to enable and disable the SIP (VoIP) ALG in the P-660H-T1v3s. To 
access this screen, click Network > NAT > ALG.

Figure 42   Network > NAT > ALG

The following table describes the fields in this screen.

Server 
Mapping Set

Only available when Type is set to Server. 

Select a number from the drop-down menu to choose a port forwarding 
set.

Edit Details

Click this link to go to the Port Forwarding screen to edit a port 
forwarding set that you have selected in the Server Mapping Set field.

Back

Click this to return to the previous screen without saving.

Apply

Click this to save your changes.

Cancel

Click this to restore your previously saved settings.

Table 26   Network > NAT > Address Mapping: Edit  (continued)

Table 27   Network > NAT > ALG

Enable SIP ALG

Select this to make sure SIP (VoIP) works correctly with port-
forwarding and address-mapping rules.

Apply

Click this to save your changes.

Reset

Click this to restore your previously saved settings.