InvisiLink™
Telephony Codec
by ViaDSP

Software Overview

The InvisiLink software package is an "intelligent telephony codec" which provides a transparent, 
low bit rate, digital connection between two analog telephony interfaces. The system can perform 
voice compression, echo cancellation, tonal (DTMF, SF, etc.) transparency, FAX, and data modem 
transparency and other functions vital in satellite and multiplexed systems. InvisiLink 
simultaneously accepts 64-kbps PCM samples and a digital bit stream, and automatically 
compresses/decompresses voice or modulates/demodulates FAX, data modem, and signaling tones.

Features and Benefits

•	Compresses 64-kbps PCM telephony signals to 2.4–16 kbps
•	Supports STUIII and data modem transparency up to V.32bis
•	High-quality voice using G.723 and G.728
•	No channel overhead (passes 9.6 FAX signa1s within 9.6-kbps digital channel)

Processor and System Requirements

•	Devices supported: TMS320C3x
•	Algorithm category: Telecommunications
•	System hardware requirements:
		40/50/60 MHz 'C3x
		32k words SRAM
		4-Mbit Flash

Algorithm Verification

Tested and fielded throughout the world in satellite and T1/El applications

Availability

•	Available now for porting
•	Evaluation/prototyping versions available on PC plug-in cards and standalone modules

Company Background and Contact Information

ViaDSP was founded to provide innovative telephony-compression products for efficient bandwidth 
management to telecom equipment manufacturers. Formed as a spin-off from DSP Software Engineering 
by one of its founders, Joel Hughes, and the entire InvisiLink development team, ViaDSP will 
continue to advance the InvisiLink product line originally created there. ViaDSP will pursue 
high-growth market areas with application-specific software, module, and chipset compression 
products.
Contact:	Joel Hughes
		ViaDSP, Inc.
		336 Baker Avenue
		Concord, MA 01742
		(508) 369-0048
		Fax: (508) 369-4868
		e-mail: viadsp@ix.netcom.com