Axis Network video Manual page 77

NETWORk TECHNOLOGIES - CHAPTER 9 77
Ports
A port number defines a particular service or application so that the receiving server (e.g., net-
work camera) will know how to process the incoming data. When a computer sends data tied to
a specific application, it usually automatically adds the port number to an IP address without
the user's knowledge.
Port numbers can range from 0 to 65535. Certain applications use port numbers that are
pre-assigned to them by the Internet Assigned Numbers Authority (IANA). For example, a web
service via HTTP is typically mapped to port 80 on a network camera.
Setting IPv4 addresses
In order for a network camera or video encoder to work in an IP network, an IP address must be
assigned to it. Setting an IPv4 address for an Axis network video product can be done mainly in
two ways: 1) automatically using DHCP (Dynamic Host Configuration Protocol), and 2) manu-
ally by either entering into the network video product's interface a static IP address, a subnet
mask and the IP address of the default router, or using a management software tool such as
AXIS Camera Management.
DHCP manages a pool of IP addresses, which it can assign dynamically to a network camera/
video encoder. The DHCP function is often performed by a broadband router, which in turn gets
its IP addresses from an Internet service provider. Using a dynamic IP address means that the IP
address for a network device may change from day to day. With dynamic IP addresses, it is
recommended that users register a domain name (e.g., www.mycamera.com) for the network
video product at a dynamic DNS (Domain Name System) server, which can always tie the domain
name for the product to any IP address that is currently assigned to it. (A domain name can be
registered using some of the popular dynamic DNS sites such as www.dyndns.org. Axis also
offers its own called AXIS Internet Dynamic DNS Service at www.axiscam.net, which is acces-
sible from an Axis network video product's web interface.)
Using DHCP to set an IPv4 address works as follows. When a network camera/video encoder
comes online, it sends a query requesting configuration from a DHCP server. The DHCP server
replies with an IP address and subnet mask. The network video product can then update a
dynamic DNS server with its current IP address so that users can access the product using a
domain name.
With AXIS Camera Management, the software can automatically find and set IP addresses and
show the connection status. The software can also be used to assign static, private IP addresses
for Axis network video products. This is recommended when using video management software
to access network video products. In a network video system with potentially hundreds of
cameras, a software program such as AXIS Camera Management is necessary in order to effec-
tively manage the system. For more on video management, see Chapter 11.