User's Manual

PMP 450 Operations Guide
Glossary
pmp-0049 (September 2012)
XI
Term
Definition
Static IP Address
Assignment
Assignment of Internet Protocol address that can be changed only manually.
Thus static IP address assignment requires more configuration time and
consumes more of the available IP addresses than DHCP address assignment
does. RFC 2050 provides guidelines for the static allocation of IP addresses. See
http://www.faqs.org/rfcs/rfc2050.html. See also DHCP.
su -
A command that opens a Linux
®
operating system session for the user root.
Subnet Mask
32-bit binary number that filters an IP address to reveal what part identifies
the network and what part identifies the host. The number of subnet mask bits
that are set to 1 indicates how many leading bits of the IP address identify the
network. The number of subnet mask bits that are set 0 indicate how many
trailing bits of the IP address identify the host.
Subscriber Module
Customer premises equipment (CPE) device that extends network or Internet
services by communication with an Access Point Module or an Access Point
cluster.
Sustained Data
Rate
Preset rate limit of data transfer.
Switch
Network element that uses the port that is associated with the physical address
of another to pass data to only the intended recipient. Compare to Bridge and
Router.
SYN/1
Second-from-right LED in the module. In the Access Point Module or in a
registered Subscriber, this LED is continuously lit to indicate the presence of
sync. In the operating mode for a Subscriber Module, this LED flashes on and
to indicate that the module is not registered.
Sync
GPS (Global Positioning System) absolute time, which is passed from one
module to another. Sync enables timing that prevents modules from
transmitting or receiving interference. Sync also provides correlative time
stamps for troubleshooting efforts.
TCP
Alternatively known as Transmission Control Protocol or Transport Control
Protocol. The Transport Layer in the TCP/IP protocol stack. This protocol is
applied to assure that data packets arrive at the target network element and to
control the flow of data through the Internet. Defined in RFC 793. See
http://www.faqs.org/rfcs/rfc793.html.
TDD
Time Division Duplexing. Synchronized data transmission with some time slots
allocated to devices transmitting on the uplink and some to the device
transmitting on the downlink.
telnet
Utility that allows a client computer to update a server. A firewall can prevent
the use of the telnet utility to breach the security of the server. See
http://www.faqs.org/rfcs/rfc818.html, http://www.faqs.org/rfcs/rfc854.html and
http://www.faqs.org/rfcs/rfc855.html.