H.264MP-MegaPixels RTSP Streaming User’s Manual
60
Possible reason:
Search NVS software adopts multicast protocol to perform searching. But the
firewall forbids multicast data packet.
Solution:
disable the firewall.
10
、
What is my public IP address
Use
http://checkip.dyndns.com/
will reply
“
Current IP Address: 116.77.192.104
”
11
、
Routers and Port Forwarding
For a collection of step-by-step guides for many common routers, please visit
PortForward.com
.
http://portforward.com/help/portcheck.htm
One of the most common devices in any given network — after computers, of course — is the
router
. Sitting between the modem and the other devices in the network, the router's job is to
route
(direct) traffic to and from the Internet and devices in the
local area network (LAN)
,
sharing a single Internet connection between multiple devices.
A router is more than just a glorified cable splitter, however; in addition to intelligently juggling
packets and priority between devices to ensure smooth data transfer, most routers include a
variety of features including Quality of Service settings, virtual private network options, web
content filtering, time-delimited access restrictions, and more.
At factory default, most routers are preconfigured with a variety of security settings, including a
firewall set to reject new incoming connections to the network. This security measure is simple,
effective, and rarely obtrusive; surfing the Internet, watching streaming video and chatting with
friends and family is uninterrupted, since these connections are established first by an
outgoing
connection
from
the LAN.
Since the router's firewall prevents Internet visitors from reaching any devices in the LAN, the
user must open a tunnel in the router's firewall to allow
specific
external connections to reach a
specific
destination device while keeping the rest of the network safe.
Port Forwarding
All TCP and UDP traffic on the Internet uses
ports
to identify the protocol being used, such as
port 80 for HTTP (web) and port 25 for SMTP (email). To solve the firewall problem and let
visitors into the network, the user instructs the router to allow traffic to pass through on a given
port. This is known as
port forwarding
, as the router
forwards
(directs) all Internet requests on
a specific port to the local machine. With port forwarding, external visitors are able to connect to
the server while other internal devices remain protected.
There are three different kinds of port forwarding:
