Quick Setup Guide

Configuring and Troubleshooting VoIP Monitoring
66 November 2013
These packet-sniffing tests are meant to verify that the NIC can be put into
promiscuous mode in order to sniff network traffic not destined for the NIC card being
tested. This is a basic requirement of the sniffing design used by CAD.
Test 4—Detect Attached IP Phones
This test detects IP phones connected inline with the NIC/PC. It uses the data
captured in Test 3. It looks for specific packets.
■ If the IP phone uses SCCP (Skinny Client Control Protocol), the test looks for
SCCP KeepAlive messages being sent from the IP phones to the Cisco Unified
Communications Manager (Unified CM). These packets have a destination
port of 2000 (default). If the port has been changed in the Unified CM, this
test might fail.
■ If the IP phone uses SIP (Session Initiation Protocol), the test looks for SIP
REGISTER messages. These are similar to the KeepAlive messages in SCCP.
Test Corrective Action if Test Fails
Open the adapter • Verify that system/kernel memory is not below 5 Mb
• Verify that the driver is loaded
Capture network
traffic
• Verify that the NIC is active
• Verify that the NIC is connected to the network and that the
cable is good
• Verify that network traffic is hitting the NIC. Another
network monitoring tool like Wireshark or a Microsoft utility
can be used to determine this. Running a browser and
accessing non-cached pages from a web server will also
determine this.