The Silent Monitoring feature will allow any premium user the ability to barge into another user's existing call, while being placed on mute, at the same time.
This feature will work similarly to when a user utilizes the *33 Star Code (Directed Call Pickup with Barge In)
At the customer's request, a specific configuration will be applied to the user's TFTP file, which will add an additional soft key (Monitor) to the user's handset.
The Directed Call Pickup with Barge-in service will need to be added to the user's profile in Broadsoft.

Polycom Configuration
<sip>
<softkey
softkey.7.label="Monitor"
softkey.7.action="!silentMonitor"
softkey.7.enable="1"
softkey.7.precede="0"
softkey.7.use.active="0"
softkey.7.use.alerting="0"
softkey.7.use.dialtone="1"
softkey.7.use.hold="0"
softkey.7.use.idle="1"
softkey.7.use.proceeding="0"
softkey.7.use.setup="0"
/>
<efk>
<version efk.version="2"/>
<efklist
efk.efklist.7.mname="silentMonitor"
efk.efklist.7.status="1"
efk.efklist.7.label="Monitor"
efk.efklist.7.action.string="*33$P1N4$$Tinvite$$Cwaitconnect$$FMicMute$"
/>
</efk>
</sip>

Steps for using the feature:
1. With the phone on hook/off hook, select the "More" soft key until you see the "Monitor" soft key
2. Select the "Monitor" soft key
3. Enter the extension of the agent/user, who is on an active phone call you want to monitor
4. Select "enter" soft key to complete the process
5. To end monitoring hang up handset
*This feature has been tested on the VVX 300/400 handsets with firmware versions 5.2.0 and 5.0.0.