ICR-1601
92
security checks of the firewall or NAT that would have otherwise restricted the traffic for not meeting its
limited filter criteria.
Special AP
The Special AP feature allows you to
request the gateway open a pre-defined
service ports for incoming packets to
pass through once the trigger port is
activated by local hosts. As shown in the
diagram, special AP rule define port 554
as trigger port and 6970~6999 as
incoming ports. With such setting, local
user at host 10.0.75.100 can enjoy the
music by using Quick Time application,
whose media server is located in the Internet. When you open application, it will activate Trigger Port and
then incoming data packet from remote application server will pass through incoming port 6970~6999.
SIP ALG
This gateway supports the SIP ALG feature to allow one SIP phone behind the NAT gateway can call
another SIP phone in the Internet, even the gateway executes its NAT mechanism between the Intranet
and the Internet. The NAT gateway monitors the control traffic and open up port mappings (firewall
pinhole) dynamically as required to know about an address/port number combination that allows incoming
packets, so it will support address and port translation for SIP application layer "control/data" protocols as
shown in following diagram. The NAT Gateway enables the SIP ALG feature, so it will monitor the SIP Phone
#1 actions, open up the required ports and make the address and port translation in a SIP voice
communication.
To Next Page
Loading...
