HSDPA
User’s Manual
WMOCEAN +420 225 371 777
http://www.wmocean.com
p. 79
NAT - Network Address Translation. NAT is an Internet standard that enables a local-area
network (LAN) to use one set of IP addresses for internal traffic and another set of addresses
for external traffic. On the gateway, NAT software performs all necessary translations of the
IP addresses. There are several purposes for NAT usage:
Provides a type of natural firewall by hiding all the internal IP addresses from the Internet.
Only the single IP assigned to the router is visible from the Internet.
Several computers on the local network to use one IP address, enabling access to the
Internet from any computer network without the need to get more IP addresses from the ISP
local computers are not directly reachable from the Internet, making them more secure
the company can use several internal IP addresses. Since they're used only internally, there
is no possibility of conflict with IP addresses used by other companies or organizations.
NTP - Acronym for Network Time Protocol. Internet standard protocol used to update the
real-time clock in a computer. It assures accurate synchronization to the millisecond of
computer clock times in a network of computers.
NTP is very useful in packet-switched, variable-latency data networks. In case of ,
if you want to measure the performances of the network, you need accurate, universal time-
stamps for the data packets.
NTP runs as a continuous background client program on a computer and it sends periodic
time requests to servers, obtaining server time stamps and using them to adjust the client's
clock. NTP uses UDP port 123 as its transport layer. It is designed particularly to resist the
effects of variable latency. There are numerous primary and secondary servers in the
Internet that are synchronized to the Coordinated Universal Time (UTC) via radio, satellite or
modem. For more information, visit
www.ntp.org
.
PBX - Acronym for Private Branch eXchange. The PBX is a small, enterprise version of the
larger central switching office of the phone company. A PBX is a private telephone switch. It
is connected to groups of trunks (junctions) from one or more central offices and to all of the
telephones at the location (subscribers, local extensions) served by the PBX. Current
exchanges are in fact PABX, automated PBX, which don’t require a human operator to route
the calls. The HSDPA equipment was designed to work together with a PABX
with analog trunks to route the calls. may be connected to the PBX either on a
trunk line or on a subscriber line (local extension).
PSTN - Acronym for Public Switched Telephone Network (s).
This is the classic international fixed telephony system based on copper wires that carry
voice and data. Analog (mostly) or digital technology is used to provide voice grade services
for the users that access that network via an analog interface. The device
connects to a PBX that has trunks going to the PSTN, so the equipment performs as an
interface between the mobile network (GSM/GPRS/UMTS) and the PSTN.
PPP - Acronym for Point-to-Point Protocol. Network protocol widely used to connect
computers to the Internet. Works on the data link layer of the OSI model. PPP sends the
TCP/IP packets of the gateway to a server that puts them onto the Internet. It is more stable
than the older SLIP protocol and provides error-checking features.
PPP is the Internet standard for dial-up modem connections, no matter if they are phone line
modems of high-speed UMTS wireless devices such as the embedded HSDPA modem of
.
PPPoE - Acronym for Point-to-Point Protocol over Ethernet. A method of secure data
transmission, PPPoE using Ethernet to connect to an ISP. The PPP traffic is sent over
Ethernet to the Internet through a common broadband medium. The users have the
appearance of "dialing" the Internet, but their computers are in fact always connected.
PPPoE supports a broad range of existing applications and services, from authentication,
accounting and secure access to configuration management. supports on the
WAN side either PPP or PPPoE connection.