The Voice Interworking Service Module (VISM) is a high-performance voice module for the Cisco MGX 8230, MGX 8250, and MGX 8850 series wide-area IP+ATM switches. This module is suitable for all service provider voice applications and offers highly reliable standards-based support for voice over ATM and voice over IP.The VISM provides toll-quality voice, fax and modem transmission and efficient utilization of wide-area bandwidth through industry standard implementation of echo cancellation, voice-compression and silence-suppression techniques.