Objective

Monitoring the line of a coworker is made possible through the Busy Lamp Field (BLF). BLF is the indicator light on an IP Phone which makes the status of another telephone in the network visible to a watcher. This feature is useful for someone who routinely handles calls for somebody else, typically a front desk clerk or a secretary. The purpose of BLF is to determine the status of another extension at a glance. It is usually configured in the web-based utility of the phone. It may also be configured on the call manager when one is being used. BLF usually has the following behavior:

• Green – The monitored line is idle and available.
• Amber – A configuration error occurred during the setup of the feature.
• Red (steady) – The monitored line is in use.
• Red (flashing) – The monitored line is ringing.

Note: BLF is not available on the Cisco IP Phone 7811.

This article aims to show you how to configure and monitor the line of your coworker through BLF on the Cisco IP Phone 7800 Series and 8800 Series Multiplatform Phones using:

• Uniform Resource Identifier (URI) — URI represents a resource from the Internet, or a server. It is typically accessible by a browser, using the http protocol. This may prove beneficial for certain applications, like deploying a simple BLF configuration.
• Extended Function — This option allows you to invoke a function. For example: fnc=sd; to invoke the speed dial function. Compared to a URI deployment, using the Extended Function allows for easier configuration when doing multiple watchers to a phone.

Note: If you are using a call manager, check its product documentation to know how to configure BLF.

Applicable Device

• IP Phone 8800 Series
• IP Phone 7800 Series

Software Version

• 11.0.1

Configure Busy Lamp Field

Using URI

Step 1. Access the web-based utility and click Admin Login > advanced.

Step 2. Click Voice > Att Console.

Step 3. Enter the BLF List URI in the BLF List URI field.

Note: In this example, the BLF List URI is 9727441325_blf.

Step 4. For Use Line Keys for BLF List, choose Yes from the drop-down menu if the line keys of the phone are to be utilized.

Note: If a Key Expansion Module (KEM) is connected, line keys on the KEM will be used after the line keys on the phone have been used up.

Step 5. Click Submit All Changes.

You should now have configured BLF using URI on the Cisco IP Phone 8800 Series.

Using Extended Function

Step 1. Access the web-based utility and click Admin Login > advanced.

Step 2. Click Voice > Phone.

Step 3. Choose the extension that will become the watcher. The status of the phone being monitored will be visible on the phone of the watcher.

Note: In this example, Line Key 4 is chosen.

Step 4. Choose Disabled from the Extension 4 drop-down menu.

Step 5. Enter the extended BLF string. In this example, fnc=blf;sub=9727441325_blf@$PROXY;ext=9727441324@PROXY is entered, where:

• Fnc = definition of the extended function.
• Ext = Extension of the speed dial.

Note: In this example, 9727441325 can monitor extension 9727441324 via line 4.

Step 6. Click Submit All Changes.

You should now have configured extended BLF on your phone.

Monitor the Line of a Coworker

Step 1. Take an incoming call on the Cisco IP Phone 7800 Series or 8800 Series Multiplatform Phone.

Step 2. On the line key of the extension found on the phone of the watcher or Key Expansion Module (KEM), verify the phone status of the extension where the call needs to be forwarded to.

Status	Busy Lamp Field	Busy Lamp Field and Speed Dial	Busy Lamp Field and Call Pickup	Busy Lamp Field and Call Park	Busy Lamp Field, Speed Dial, and Call Pickup	Busy Lamp Field, Call Park, and Call Pickup	Busy Lamp Field, Speed Dial, and Call Park	Busy Lamp Field, Speed Dial, Call Pickup, and Call Park
Idle
Alerting
In use
Call parked	-	-	-		-
Error

• Green LED — This means that the line being monitored is available. A call can be forwarded.
• Red LED — This means that the line being monitored is busy. A call can be forwarded, but it may be dropped, or forwarded to the voice mailbox, depending on the call forwarding rule.
• Blinking red LED — This means that the line being monitored is ringing. Treat this as a line with a red LED.
• Amber LED — This means that a configuration error occurred while the feature was being set up.

You have now determined the status of the line.