ZyXEL Communications VMG1312-B Series - 11.6 The ALG Screen; 11.7 The Address Mapping Screen

Chapter 11 Network Address Translation (NAT)
VMG1312-B Series User’s Guide
194
11.6 The ALG Screen
Som e NAT routers m ay include a SI P Applicat ion Layer Gat eway ( ALG) . A SI P ALG allows SI P calls
to pass through NAT by exam ining and translating I P addresses em bedded in t he data stream .
When t he Device registers with the SI P regist er server, t he SI P ALG t ranslat es the Device’s private
I P address inside the SI P data st ream t o a public I P address. You do not need t o use STUN or an
outbound proxy if your Device is behind a SI P ALG.
Use t his screen to enable and disable the NAT and SI P (VoI P) ALG in the Device. To access this
screen, click N et w ork Sett ing > NAT > ALG.
Figure 81 Net work Sett ing > NAT > ALG
The following t able describes t he fields in t his screen.
11.7 The Address Mapping Screen
Ordering your rules is im port ant because the Device applies the rules in t he order that you specify.
When a rule m atches t he current packet, t he Device takes the corresponding act ion and the
rem aining rules are ignored.
Click Ne t w or k Set t ing > N AT > Address Ma pping to display t he following screen.
Figure 82 Net work Sett ing > NAT > Address Mapping
Table 58 Network Sett ing > NAT > ALG
LABEL DESCRIPTION
NAT ALG
Enable t his t o m ake sur e applications such as FTP and file transfer in I M applicat ions work
correctly with port- forwarding and address- m apping rules.
SI P ALG
Enable t his t o m ake sur e SIP (VoI P) works correctly with port- forwarding and address-
m apping rules.
Apply Click Apply t o save your changes.
Cancel Click Ca nce l t o rest ore your previously saved settings.