Quadrox QGuard Installation Manual - Manual (Page 24)

GuardNVR Installation Manual 24
Version 4.4 Series
family of related network languages, called network protocols. These TCP/IP protocols are the
network protocols used on the Internet and on most networks throughout the world today.
GuardNVR uses two protocols specifically: TCP and UDP.
A communication channel on a TCP/IP network can be represented as a tunnel with two
endpoints. The two programs communicating with one another are each said to be at each
endpoint. These endpoints are called ports.
When the two programs communicating with one another are not located on the same
corporate network (like most communication between a program on a client PC and a program
running on another computer on the Internet), often there is some kind of guardian device in
between them. These guardian devices are called Firewalls. Their job is to guard all network
communication between the corporate network and the Internet and block certain unwanted
communications while allowing the desired communication to pass.
There are several levels on which a firewall can guard network communication. The most
common way is to allow or disallow certain ports to be used, depending on which applications
are allowed to communicate.
A firewall guards a port in a certain direction. Communication that is initiated from the
Internet towards the corporate network is called incoming traffic, while communication from
the corporate network towards the Internet is called outgoing traffic. Note that the initiation of
the communication is important: once a connection is made, data can be transferred in both
directions.
Let’s apply this principle to GuardNVR network communication. The GuardNVR client (the
ActiveX component embedded in Internet Explorer at the client machine) will try to create
network connections to the GuardNVR server. The eventual result of these connections will be
video data streaming from the GuardNVR server to the GuardNVR client, but since the
GuardNVR client initiates them, they are referred to as connections towards the GuardNVR.
From the client perspective, it is outgoing traffic, while for the server it is incoming traffic.
In order for the GuardNVR to function correctly, the appropriate ports need to be
opened for communication towards the GuardNVR.
There are three port configurations to perform:
1. TCP Port 80: to allow external users to see the web interface (HTTP traffic). This port
is usually opened by default.
Some ISPs block port 80. Please inform yourself.
2. TCP Port 1518: to allow external users to receive alarms, control PTZ cameras, send
commands, etc. This is called the GuardNVR control signal.
3. UDP Ports 4096 till 4223: By default the GuardNVR uses a range of UDP ports to
transport video streams. These UDP ports are not listening all the time. The GuardNVR
software enables them at random to enhance security.
Typically when the UDP ports are not opened correctly, the user only sees the web-
interface but no live images.