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Commissioning instructions OZW775 V2.01
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HVAC Products
Appendix
22.06.2012
7.2.9 Terms and abbreviations on Ethernet and Internet
Upstream and downstream channel transport data at different rates, i.e. asymmetrically
via a two-wire line (DLS, copper phone line) on a broadband network.
When your surf the Internet only little data is sent upstream, i.e. to the server. The re-
quested data, however, are sent at high speed downstream to the requesting computer.
You can call or e.g. send faxes while transmitting data.
The Internet Service Provider ISP provides the ADSL connection. You need a DSL
modem for this type of connection.
A client is a network device unable to execute certain services and thus requests those
services from the server. The server provides the service and sends a reply.
See also Standard gateway
The DHCP server allows for dynamic assignment of an IP address to network devices.
Routers also support this function.
The bit rate describes the transmission speed or rate in bits per second (bps).
The DNS allows for assigning IP addresses to names (that are easier to remember
than 32-bit IP addresses). A DNS server must manage this information for each LAN
with Internet connection. When you select an Internet page, the web browser accesses
the IP address of that site assigned by the DNS server to open a connection.
On the Internet, domain names are assigned to IP addresses as per a hierarchical
system. A local PC only knows the address of the local DNS server. This server, in
turn, knows the addresses of all PCs on the local network as well as that of the higher
DNS servers that, in turn, know the addresses of the next higher DNS servers.
The domain name is the web server designation on the Internet. The DNS server
assigns an IP address to the domain name.
A DoS attack is a special type of hacker attack on computers and networks with con-
nection to the Internet. The DoS attack aims at disabling computers and networks to
prevent network resources from being provided and services from being executed.
DSL is a type of data transmission allowing for 1.5 Mbps access to the Internet on
standard copper phone lines. The Internet Service Provider ISP provides the DSL
connection. You need a DSL modem for this type of connection.
The DSL router has several functions. It connects the Ethernet network (LAN) and the
internal network devices to the Internet. The router then requests the IP addresses for
the internal network devices from the DNS server. Port forwarding (NAT, PAT) is also
configured in the router. In addition, service "DynDNS", which automatically is updated
after a change of the DynDNS server, is activated in the router.
ADSL (Asymmetric Digital
Subscriber Line)
Client
Default gateway
DHCP (Dynamic Host
Configuration Protocol)
Bit rate
DNS (Domain Name
System)
Domain name
DoS attack (Denial of
Service)
DSL (Digital Subscriber
Line)
DSL router
