Persistent Packet Loss on T1 Connection
Posted on 2010-09-20
We have a bonded-T1 connection at our office we use for our internet access and phones. It has been is use just over a year. For the first 11 to 12 months it has served us fine. However, over the past couple of months we are seeing a persistent 2%-4% packet loss. We see this by running constant pings both to our T1 gateway as well as sites like MSN, Yahoo, Goodle, etc.
Our T1 provider insists the lines are clean and error free plus they've replaced all our on-site equipment. The phone company providing the local loop insists the lines are clean. They've pointed the finger at our firewall.
Our network config is not complicated. The T1 connection runs straight into our Firewall which is an Astaro Security Gateway running version 7.507. From there we have a NetGear gigabit switch serving around 20 Windows (2000 through 7) and Mac machines plus a few iPhones, Droids, BlackBerries that connect to a WiFi (airport) we have set up. We use a Windows 2003 SBS as a domain server.
We disconnected the T1 from our network and plugged it directly into a laptop and pinged our gateway same as we had been doing before. Much better. There were only 2 timeouts after running for 20 minutes. So, we thought, maybe it WAS our firewall. To test, we dusted off an old Astaro V6 firewall that was no longer in use and hooked it up. Same result! Right about 4% loss! This leads me to believe it could be something on our internal network causing the trouble?
Any ideas what could be causing this or suggestions of tools for tracking this down? I've downloaded pingplotter and wireshark but I'm a software developer by trade so I'm not sure how to interpret much of their networking mumbo-jumbo.
Our internet access is still usable and on a good day our throughput measures around 2600 kbps up and down. But the frequent packet loss causes delays or timeouts in page loads, disconnections of FTP and webinars. The majority of use is simple web browsing. The timeouts and disconnections continue over night even with little activity.
Our phone lines are not used heavily. Rarely is more than one person on the phone at a time so that should not be a problem as far as our bandwidth over the T1s is concerned.