User manual
LinkMAX HSA300 ADSL Ethernet Router User’s Guide  Appendix D. Glossary 
 137 
SNMP  Simple Network Management Protocol 
The TCP/IP protocol used for network management. 
splitter  A device that splits off the voice component of the DSL signal to 
a separate line, so that data and telephone service each have 
their own wiring and jacks. The splitter is installed by your 
telephone company where the DSL line enters your home. The 
CO also contains splitters that separate the voice and data 
signals, sending voice to the PSTN and data on high-speed lines 
to the Internet. See also CO, PSTN, splitterless, microfilter. 
splitterless  A type of DSL installation where no splitter is installed, saving 
the cost of a service call by the telephone company. Instead, 
each jack in the home carries both voice and data, requiring a 
microfilter for each telephone to prevent interference from the 
data signal. ADSL is usually splitterless; if you are unsure if your 
installation has a splitter, ask your DSL provider. See also 
splitter, microfilter. 
subnet  A subnet is a portion of a network. The subnet is distinguished 
from the larger network by a subnet mask which selects some of 
the computers of the network and excludes all others. The 
subnet's computers remain physically connected to the rest of 
the parent network, but they are treated as though they were on 
a separate network. See also network mask. 
subnet mask
  A mask that defines a subnet. See also network mask.
TCP  See TCP/IP. 
TCP/IP  Transmission Control Protocol/Internet Protocol 
The basic protocols used on the Internet. TCP is responsible for 
dividing data up into packets for delivery and reassembling them 
at the destination, while IP is responsible for delivering the 
packets from source to destination. When TCP and IP are 
bundled with higher-level applications such as HTTP, FTP, 
Telnet, etc., TCP/IP refers to this whole suite of protocols. 
Telnet  An interactive, character-based program used to access a 
remote computer. While HTTP (the web protocol) and FTP only 
allow you to download files from a remote computer, Telnet 
allows you to log into and use a computer from a remote 
location. 
TFTP  Trivial File Transfer Protocol 
A protocol for file transfers, TFTP is easier to use than File 
Transfer Protocol (FTP) but not as capable or secure. 
TTL  Time To Live 
A field in an IP packet that limits the life span of that packet. 
Originally meant as a time duration, the TTL is usually 
represented instead as a maximum hop count; each router that 
receives a packet decrements this field by one. When the TTL 
reaches zero, the packet is discarded. 
twisted pair  The ordinary copper telephone wiring long used by telephone 
companies. It contains one or more wire pairs twisted together to 
reduce inductance and noise. Each telephone line uses one pair. 
In homes, it is most often installed with two pairs. For Ethernet 
LANs, a higher grade called Category 3 (CAT 3) is used for 
10BASE-T networks, and an even higher grade called Category 










