Instruction manual

TCP/IP Internet Basics

PORT FORWARDING

Port forwarding is a feature in many routers that allows a device serving data within a local

network to be accessed from outside the network (i.e. Internet). By default routers block

requests from the outside if they haven’t been initiated from within the local network. The

router basis these requests on the application’s TCP and/or UDP port number. The NVS uses

2 TCP ports. Consider the scenario in which a NVS is attached to a router. Without port

forwarding configured on a router, a program outside the local network requests a connection

to port 8888 (web port on our NVS), but is denied access as a security measure by the

router. So therefore, if you are connecting an NVS to a router and that NVS is using a Private

IP address, you MUST configure port forwarding on that router to tell the router to forward

the ports to your NVS rather than block it. More information on port forwarding configuration

is stated in the FAQ section.

Switch

: A switch basically connects multiple devices together that are located on the same local

network. These typically have many more ports than a router, generally anywhere from 5

switched ports to 48 switched ports. You can simply just connect a switch to a router to extend the

amount of ports, thus devices allowed on the network or to share an Internet connection. Unless

you have more than four devices on your local network, then you should be able to use the

available ‘switched’ ports on your router to share an Internet connection. In many enterprise

networks, a patch panel or closet is used to house several switches that connect all the networked

devices on that location. For this tutorial’s sake, switches will not be used. We will implement a

single home office router. Switches are not used to connect networks, this is why you cannot use a

switch alone to share an Internet connection.

Modem

: A modem converts the electrical signals from your Internet provider to a signaling type

that your computer or router can understand. Without a modem, the computer or TCP/IP device

would not be able to understand the signaling method used by cable TV and telephone service

providers. A modem will typically have one RJ-45 Ethernet port and one other port to

accommodate either a cable TV coaxial cable or a DSL telephone line from your Internet service

provider. Overall you will have the line from your ISP entering the modem and from the modem to

your router’s WAN port via a network cable. So that way the signal has been converted by the

modem and also leads to your router, which separates your local network from the ISP’s network.

Ethernet and RJ-45:

Ethernet is a popular communications protocol (language) used for multiple devices to ‘talk’ to each

etwork Video Server User’s Manual

B01