You can’t argue with that logic, you simply plug the butt set in at different places in your telephone network to check for service. BTW, a butt set is a test phone that was normally carried around by a telephone technician for testing. Clipped to a tool belt, it usually was swinging on the backside of the belt, near the……well you get it.
Today, a technician needs the ability to do testing like that to see where issues are in the network, and you can do this with the right equipment. Let me give you an example. You have a network with a Router, a Firewall, a SIP server, and computers and phones. We’ll use a small network as our sample, but it will scale to larger networks as well.
For this solution, we are going to use a 48port POE Switch. In my example, I used an HP 2610, but you can use your preferred switch. This particular switch supports vlan tagging, layer 3 switching, and most importantly, port mirroring. Port mirroring allows you to direct a copy (mirror image) of all packets on a port to another port so you can take the mirrored traffic to view in real time.
What we will do is take ports 1 and 2 of the switch and put them into their own untagged vlan, we will call it vlan 31. Our Internet connection will plug into port 1. Port 2 will be connected to the WAN side of our router.
Next we will take ports 3 and 4 and put them into their own vlan as well. We will cal this vlan 37. The Lan side of our Router will connect to port 3. Port 4 will connect to the wan side of our Firewall.
We have just created a chain through the ethernet switch that provides a test point in front of the router, behind the router, in front of the firewall, and behind the firewall. By using port mirroring on the switch, we can direct a copy of all traffic to any of those ports to a port that our wireshard packet capture machine is on and get great troubleshooting capability at any of those ports.
By having our phones, servers, etc. on their own ports, we can drill into any of them as well to look at the specific traffic on each port.
It’s not a butt set, but you don’t have to carry it around either. Yet, you can follow traffic around on your network, point by point by point. You can simply redirect your port mirror to the port your packet capture device is on, and do custom captures as your troubleshooting of your network.
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