
SpeedStream Router User Guide 
Appendix D:
Acronyms and Technical ConceptsAcronyms
AAL5  ATM Adaption Layer 5 
ADS  Attack Detection System 
ATM   Asynchronous Transfer M ode 
ATU   ADSL Termination Unit 
ATU-C  ADSL Termination Unit - Central Office; refers to location at the CO 
aggregation point. 
ATU-R  ADSL Termination Unit - Remote; refers to location at the customer premises 
CHAP   Challenge-Handshake Authentication Protocol 
CRC  Cycle Redundancy  Checking 
CO   Central Office 
DDoS  Distributed Denial of Service 
DHCP   Dynamic Host Configuration Protocol 
DMZ  Demilitarized Zone 
DNS   Domain Name Service 
DSL   Digital Subscriber Line 
DSLAM   Digital Subscriber Line Access Multiplexer 
Ethernet  Network standard for LAN communications 
FEC  Forward Equivalence Class 
firmware   Software, in binary form, stored within a flash PROM 
frames  Data packet 
Gateway Router 
GUI  Graphical User Interface 
ICMP   Internet Control Message Protocol 
IGD  Internet Gateway Device 
IPCP   IP Control Protocol 
ISP   Internet Service Provider 
LCP   Link Control Protocol 
LLC  Logical Link Control layer 
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