IronPort Systems ES-1528 User Manual

ES-1528 User’s Guide

This chapter shows you how to give higher priority to Voice over Internet Protocol (VoIP) 
packets over other data packets as they pass through the switch.

Voice over Internet Protocol (VoIP) allows telephone calls to be made over a data network 
like the Internet. With the increased prominence of delay-sensitive applications (voice, video, 
and other multimedia applications) deployed in networks today, proper QoS configuration 
ensures high-quality application performance. 
The Auto VoIP feature is intended to provide an easy classification mechanism for voice 
packets so that they can be given high priority in order to provide better transmission resulting 
in higher sound quality for the end users.
The AutoVoIP feature explicitly matches VoIP packets in Ethernet switches and provides 
them with the highest class of service. The AutoVoIP feature provides the capability to assign 
the highest priority for the following VoIP packets:

• SIP – Session Initiation Protocol is an internationally recognized standard for 

implementing VoIP. SIP is an application-layer control (signaling) protocol that handles 
the setting up, altering and tearing down of voice and multimedia sessions over the 
Internet.

• MGCP – Media Gateway Control Protocol is a control and signal standard for the 

conversion of audio signals carried on telephone circuits (PSTN) to data packets carried 
over the Internet or other packet networks.

• SCCP – Skinny Client Control Protocol is a Cisco proprietary protocol used between call 

managers and VoIP phones. 

Use the  Auto VoIP Settings enable automatic assignment of high priority to VoIP packets 
passing through the switch. Click Auto VoIP in the navigation panel to view the following 
screen.