• Frame Relay and ATM routers and switches introduce large, variable and unpredictable delays
• Echoes from the Public Switched Telephone Network (PSTN) in combination with the delays from Frame Relay and ATM equipment yield objectionable speech quality

Quad E1 VCL-EC, E1 Echo Canceller Advantages

USER PROGRAMMABLE tail-side. Echo Cancellers are always required to be installed, such that, the tail-side of the echo canceller always faces towards the source of the echo. Our E1 Echo Cancellers have a user configurable tail-side so that the user may remotely change the direction of the tail-side of the echo canceller - without having to physically change the E1 connections on the echo canceller card.

USER PROGRAMMABLE Signaling Option. Our Echo Cancellers provide user programmable signaling options. The E1 signaling protocols that we support are 30B+D PRI ISDN (Euro ISDN) signaling, 31B (31 voice channels) with out-of-band signaling, R2 CAS Signaling, SS7 Signaling (on any user selected time-slot). All signaling options are USER SELECTABLE.

Quad E1 VCL-EC, E1 Echo Cancellers Support 2100 Hz fax / analog data modem tone detection and echo canceller disabling on all channels. For dedicated digital data or video channels, if you wish to assign certain specific times-slots of the E1 circuit for dedicated video you may do so, using our E1 echo cancellers. Our E1 echo cancellers allow the user to program / assign dedicated time-slots for digital data or video transmission. The user may specify / define the dedicated data channels so that they are always bypassed from the echo cancellation circuitry - leaving those dedicated time-slots for digital data communication / dedicated video transmission only.

USER PROGRAMMABLE dedicated data channels. The user may specify / define the dedicated data channels so that they are always and completely bypassed from the echo cancellation circuitry - leaving those specifically assigned dedicated time-slots for digital data transmission (including video transmission).

Features and Highlights

• User Selectable - 128ms - Unidirectional or 64ms - Bidirectional. The user selection is made through a user configurable software interface command
• Compliant to ITU-T G.164, G.165, G.168 2000, G.168 2002) requirements
• Carrier-grade voice quality per AT&T Voice Quality Assessment Lab
• Fax / Modem G.164, G.165 - 2100 Hz tone disable as per ITU-T G.164/G.165 Recommendations. Allows fax and analog modem data transmission through automatic echo cancellation enable / disable function
• Disable Tone detection supported on all audio paths
• Fully integrated independent 30-channel voice echo canceller
• Option for user to select data or voice channels for selective echo cancellation. This feature allows the user to use selected time-slots for data transmission to enable digital data / CCS signaling transmission
• Transmission (data mode), while keeping the echo cancellation "ON" on the remaining time-slots (voice mode), on which echo is required to be cancelled
• E1 Circuit by-pass in event of power supply failure. This feature enables the by-pass of the E1 Circuit in the event of power failure. This ensure continues signal even if the power to the echo canceller fails
• E1 Circuit by-pass on power failure
• E1 Circuit by-pass on Echo Canceller card removed. This feature allows the user to by-pass the E1 Circuit by simply removing the echo canceller card. E1 circuit connects "through" as soon as echo canceller is removed from its slot
• Non-Linear Processor with adaptive suppression threshold and comfort noise insertion
• Programmable Double-Talk detection threshold
• Narrow-Band signal detection
• Adjustable Gain/loss settings on all channels. Provides the user the flexibility to adjust and optimize the voice and transmit receive levels
• Signaling Support:
  • 30B+D PRI ISDN (Euro ISDN) signaling
  • 31B (31 voice channels) with out-of-band signaling
  • R2 CAS Signaling
  • SS7 Signaling (on any user selected time-slot)
  • All signaling options are USER SELECTABLE / USER CONFIGURABBLE
• Redundant Power Supply (Optional)
• Non-Linear Processor with Comfort Noise Insertion
• TCP / IP remote access for remote configuration and control
• Assures operability with V.32 / V.32bis / V.34 modem and fax transmissions Conforms to standards assuring proper public network operation and facilitating system integration.
• Removes residual echo and minimizes switching effects thereby providing high perceived speech quality. Unique design provides the industry's best sounding single chip echo canceller
• Ensure echo canceller maintains excellent performance at all times in the presence of non-echo voice signals. Useful for trunks that have very low echo-returns loss
• Ensure echo canceller maintains excellent performance at all times in presence of tones or signals including DTMF tones
• Instability detector suppresses variable pitched ringing or oscillation
• Path change detect permits fast re-convergence when a major change occurs in the echo channel
• User selectable tail-end side. This feature allows the user to select the "Tail-End" side of the Echo Canceller. The "Tail-End" side of Echo Canceller is that part of the network which generates / causes to generate the Echo. Unidirectional Echo Cancellers must always be installed on far-end of any network from the point at which an Echo is being heard. The "Tail-End" side must always face the "Source Side" of the network which is generating the echo. Ideally suited to handle most echo situations
• Usable in telecommunications systems worldwide. Able to interface in most systems where linear samples are available

The Quad E1 VCL-EC, E1 Voice Echo Canceller, 32 per Shelf / Chassis, fitted with a backplane that provides rear access of all external interfaces. The E1 interface, power input, alarm extension are all accessed from the system backplane.

Front View of the Shelf