Glossary (E)

# - A - B - C - D - E - F - G - H - I - J - K - L - M - N
O- P - Q - R - S - T - U - V - W - X - Y - Z

E-1
The European interface for PRI ISDN lines. An E-1 connection has up to 30 B channels and 1 D channel, which transmit at rates of up to 2.048 Mbps.

E.164
The term “E.164 number” differentiates an “absolute” telephone number from the number you must dial to reach an endpoint from a specific location. E.164 numbers include country codes, national destination codes and subscriber numbers.

ECHO CANCELLATION
A process which attenuates or eliminates the acoustic echo effect on video conference calls. Echo cancellation is largely replacing obsolete echo suppression.

ECHO EFFECT
A time-delayed electronic reflection of a speaker's voice. This is largely eliminated by modern digital echo cancellation.

ECHO SUPPRESSION
A technique for reducing annoying echoes in the audio portion of a video conference by temporarily deadening the communication link in one direction.

EDGE
A mobile data service available to users of GSM mobile phones. Provides higher bandwidth than GPRS. Typically referred to as 2.75G.

ENDPOINT
A network element at the end of the network such as an H.323 terminal, a Gateway, an MCU, a PC terminal, IP or ISDN phone, or video camera.

ETHERNET
A LAN physical and data link protocol running over the lowest two layers of the OSI Reference Model at speeds of up to 10,100 or 1000 Mbps.

ETSI (EUROPEAN TELECOMMUNICATIONS STANDARDS INSTITUTE)
A France-based non-profit organization that produces telecommunications standards used throughout Europe and beyond.

EV-DO and EV-DO Rev. A (EVOLUTION-DATA OPTIMIZED)
A wireless radio broadband data standard adopted by many CDMA mobile phone service providers in Japan, Korea, the Czech Republic, Russia, Latvia, Romania, Portugal, Brazil, Israel, the United States, Australia, Canada, New Zealand, Venezuela, Angola, Mexico, and Puerto Rico. It is standardized by 3GPP2, as part of the CDMA family of standards.

EVRC (ENHANCED VARIABLE RATE CODEC)
A speech codec used in CDMA networks.

EXIT ZONE
When you define a prefix for the Exit Zone Service, you need to dial the prefix to reach an endpoint in another zone. This can be useful for restricting unauthorized users from making calls to other zones. The Exit Zone prefix affects the way in which the Gatekeeper tries to complete calls to other zones.