Most online gaming does not require huge amounts of information flowing back and forth between the game system and a game server on the Internet. What it requires is low latency, i.e. the amount of time it takes for a packet to travel from the games system to the game server and back. Latency is caused by delays in forwarding the packet to the next hop along the packet’s route to and from the game server. Delays occur at various points along the way, so many things contribute, but often there is a bottleneck that slows everything down. Usually the bottleneck is due to available bandwidth. If there is not enough bandwidth, the packet must wait in a queue until its turn to get forwarded; the greater the congestion, the longer the wait. The Housing network most typically encounters over-saturation of bandwidth usage between 2-6pm but can expand to noon to midnight as finals approach.
It really boils down to 2 options; either buy more bandwidth, or prioritize the traffic. Bandwidth is measured in megabits per second (mbps) and for commodity bandwidth (typical Internet traffic to .com’s) it costs about $1000 per 1 mbps per year. Housing has been increasing the bandwidth every year for the last 5 years. It was at 50 mbps 5 years ago during the day and 75 mbps at night. Now it is 720 mbps from 7 a.m. to 6 .p.m. and 1000 mbps at night and all weekend. Also, during the run up to finals, ACNS usually robs main campus bandwidth and gives some to us. Total annual operational cost for bandwidth for Housing alone was $612,000 in 2010 (including infrastructure fees paid to ACNS). The reason why there is a major jump of bandwidth from 6pm – 7am week nights and weekends is that ACNS lets us share the extra bandwidth not being used by main campus during that time, otherwise we would be stuck at the lower rate all the time.
The main culprit for bandwidth hogging is file sharing and bittorrent. I’ll assume all know what those are and not get into a discussion as to the issues of its use. These programs would and do use every available bit of bandwidth they can get. Some other high bandwidth programs are Skype, if the user’s system is acting as a Skype router, YouTube, and other streaming video feeds like Netflix and Hulu. If games try to compete with these programs they lose because the others have so many more packets, the occasional packet to a game server gets buried in the queue. It eventually makes it, but it takes time.
The PacketShaper, which you may hear about from the Help Desk, is a traffic shaping device that prioritizes the packet queue. The idea is to allocate a certain amount of bandwidth for a certain type of traffic. This would work better if it could perfectly identify the type of traffic a packet belongs to. File sharing software programs uses encryption or other techniques to get around prioritization of traffic so they won’t get identified and blocked/restricted. They are a moving target. Gaming traffic is a little easier to distinguish, but changing servers, port numbers, etc… make it a moving target also. Our strategy has been to try to have the PacketShaper identify gaming traffic and give it the highest priority. Next it tries to identify FileSharing traffic to restrict it to only 10mbps of bandwidth maximum for all. Finally, each residence hall and apartment complex are given a guaranteed amount of traffic and a burst rate (usually 3 times the guaranteed bandwidth) so that if there is unused bandwidth at that moment, then it can be used if needed. That way there is a large pool of available bandwidth throughout the system for first-come first-serve access to the Internet. Some other traffic may have low priority, specifically ping (ICMP echo/reply). This is what is commonly used for latency checks. While repeated pings to Internet servers may give a relative sense of what the latency is, it is not a true measure.
We could throw bandwidth at the problem every year and it will help for a little while. This is needed to some degree for sure, but there are newer technologies that do not attempt to look at individual packets and classify it as a type of traffic. Instead, it tries to indentify and control individual “flows” or streams of traffic related to a single user/IP address. We are researching a replacement for the PacketShaper with a newer systems so that we can better regulate bandwidth usage. For those that use little bandwidth, a.k.a. gamers, it should work a lot better.
We are taking steps daily, as well as planning long term, on how to address your needs. If you contact the Housing Technology Help Desk (970-491-4734), be assured we will do our best to improve your network access given the limitation. If there are special circumstances/events, or you want to help us troubleshoot a specific game, let us know and we can often work something out on a temporary basis. If you have more questions or comments, please don’t hesitate to contact the Help Desk.
If you are interested, there is an HDS network information email list serv that provides us with a way of interacting with gamers and trying to resolve network issues. Please go to https://lists.colostate.edu/cgi-bin/mailman/listinfo and click on “Hds_network_grp” and follow the instructions to subscribe to this list-serv. We try to be responsive to the gaming community, but please realize that the network staff must respond to academic and general network access issues first.
If you are getting a Strict NAT type on your gaming device, please call our helpdesk at 970-491-4734 or email HDS_Helpdesk@mail.colostate.edu with your name, CSU ID number, your room number, and the number of the wall port you are plugging your device into.