In this lab, we will use a protocol analyzer to capture a complete SIP call. We will analyze the headers and the message flow. You can create this environment with a PC and two UACs. The UACs can be Softphones, ATAs, or even IP phones.
Note
Adapt this lab to your needs.
Start capturing packets using
ngrep
. If it is not installed, install it using:apt-get install ngrep
To capture the packets use:
ngrep –p –q –W byline port 5060 >test.txt
Configure the UACs (Softphones, IP phones, or ATAs).
Configure the first UAC with the following configuration:
sip proxy 10.1.x.y – IP of your proxy
user: 1000
password: 1000
Configure the second UAC to the following configuration:
sip proxy 10.1.x.y – IP of your proxy
user: 1001
password 1001
After configuring the devices, you will need to register the IP Phone. Not all devices do auto registering.
Check if the phone is registered using:
openserctl ul show
At...