E1 120 4P VOICEBAND SERVICES CARD clei The Voiceband Services Card (VSC) terminates TDM channels at its 120 ohm E1 ports, and provides features including speech compression, silence removal, and fax demodulation to adapt these TDM channels to transport ov

E1 120 4P VOICEBAND SERVICES CARD clei The Voiceband Services Card (VSC) terminates TDM channels at its 120 ohm E1 ports, and provides features including speech compression, silence removal, and fax demodulation to adapt these TDM channels to transport over an ATM network. The VSC requires a minimum of one (typical applications require three) and a maximum of three DSP1 transport modules per 90-4654-01 or 90-4654-02. Fits 7470.