RAD Data comm Modular Access Device with Integrated Router 사용자 설명서

Appendix D  Glossary 

FCD-IPM Installation and Operation Manual 

D-4  

 

 - Spoofing is a technique used to reduce network overhead, especially in 

a WAN. Some network protocols send frequent packets for management 
purposes. These can be routing updates or keep-alive messages. In a WAN this can 
introduce significant overhead, due to the typically smaller bandwidth of WAN 
connections. 
Spoofing reduces the required bandwidth by having devices, such as bridges or 
routers, answer for the remote devices. This fools (spoofs) the LAN device into 
thinking the remote LAN is still connected, even though it's not. The spoofing saves 

the WAN bandwidth, because no packet is ever sent out on the WAN. 
SPX (Sequenced Packet Exchange)

 - SPX is a transport layer protocol built on top 

of IPX. SPX is used in Novell NetWare systems for communications in client/server 
application programs, e.g., BTRIEVE (ISAM manager). 
Static Station

 - A static station is a host, which is added manually to an ARP or 

LAN table. 
Stop Bit

 - Stop Bits mark the end of a unit of transmission (normally a byte or 

character). In serial communications, where each bit of the message is transmitted 
in sequence, stop bits are extra "1" bits which follow the data and any parity bit. 
Synchronous Transmission

 - Synchronous transmission is when data bits are 

transmitted at a fixed rate. The sender and the receiver are synchronized. 
TCP (Transmission Control Protocol)

 - TCP is the most common transport layer 

protocol used on Ethernet and the Internet. 
TCP is built on top of Internet Protocol (IP) and is nearly always seen in the 

combination TCP/IP (TCP over IP). It adds reliable communication, flow-control, 
multiplexing and connection-oriented communication. It provides full-duplex, 
process-to-process connections.  
TCP is defined in STD 7, RFC 793. 
TCP/IP stack (Transmission Control Protocol over Internet Protocol)

 -TCP/IP 

stack is the standard Ethernet protocols incorporated into 4.2BSD UNIX. While 
TCP and IP specify two protocols at specific layers, TCP/IP is often used to refer to 
the entire DoD protocol suite based upon these, including Telnet, FTP, UDP and 
RDP. 
TFTP (Trivial File Transfer Protocol )

 - TFTP is a simple file transfer protocol used 

for down-loading boot code to diskless workstations. 
Throughput

 - Throughput is the amount of data a communications channel can 

carry, usually in bytes per second. 
UDP (User Datagram Protocol)

 - UDP is an Internet standard network layer, 

transport layer and session layer protocols which provide simple but unreliable 
datagram services. It adds a checksum and additional process-to-process 
addressing information. UDP is a connectionless protocol which, like TCP, is 
layered on top of IP. 
UDP is defined in STD 6, RFC 768. 
WAN (Wide Area Network)

 - A WAN is a network, usually constructed with serial 

lines, extending over distances greater than one kilometer.