Saturday, November 27, 2010

IT adventures at home

At home I have a reasonably complicated network 11 devices in total that need to connect to our network. Our network consists of 3 routers and 1 wifi access point (not the primary gateway like most home setups).

There are a total of 7 devices on the hard line and the remaining 4 exist purely on wirelsss.

Once a network gets this large some level of network management is required. In our network setup each zone exists in it's own IP range (still on the same subnet) and wireless is served in it's own subnet entirely.

The 3 routers have divided duty as:


The gateway is the most powerful of the 3 routers it's duty is to take care of QoS and firewall duties. As well as run the DHCP.

the internode is the linking point that distributes traffic it primarily operates as a switch and access point joining the wireless network to the primary network. It exclusively handles wireless traffic and isolates it from the network.

The downlink connects to the home server. The downlink also performs additional QoS functions as it is connected to the home server. The server is often throttled during peak times when other clients need to utilize more bandwidth.

With all this network management I was horrified when some random Chinese programs some family members installed just took down the entire network by using every last drop of upload bandwidth.

I recently discovered 2 offenders on my network PPStream and UUSee both are chinese P2P streaming programs and both analyse how much bandwidth you have in the upload channel and attempt to use up all of it. Unfortunately on modern routers with QoS still can't set a static maximum upload per host rule. Or more ideally the rule will be written as:

Allow burst traffic for up to 5 min (upload unrestricted). Then:
Throttle any additional upload from that host until their upload is less than 50% of the allotted cap.

Essentially a host would have to be transmitting past a set rate say more than 70% of your total upload capacity for a full 5 min before the throttle kicks in and it fixes the situation. Normal browsing wouldn't trigger this gaming wouldn't trigger this as most games don't have very high upload demands unless your the server. VoIP should get through just fine. And P2P software that allows the user to set limits would also work just fine. But those Chinese streaming software are particularly nasty and there's very little you can do to limit their rates.

Failing to communicate effectively to less technical users that they were essentially making our network unusable I resorted to a software solution. "NetLimiter 3 Lite" is employed currently on a trial basis to see if it can resolve the situation. Net limiter is unique in that it allows you to throttle on the client and on a per software basis. The offending pieces of software are now given a reasonable amount of bandwidth to work properly and so far the network seems to have recovered.

I'd recommend giving it a shot if your the network admin and you have control over client machine administration.

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