Monday, 21 February 2011

Bandwidth capping criticisms

In the past, Optimum Online imposed bandwidth caps on its users. Users reported that after an undefined period of continuous upload usage, they have been capped from 2 megabits upstream to 150 kilobits upstream, a 92.5% decrease in upstream bandwidth. There is no information available to the consumer about OOL's capping policy[4][5]. Getting uncapped is an often lengthy process, requiring OOL representatives to call a customer back at their house. The criteria for getting capped seems to differ from customer to customer. Cablevision claims that the decision is based on the CPU *utilization* of their gateway servers, and they cannot give a customer any parameters with which they can avoid capping. They claim to offer only "burst upload service". Discussions by capped OOL customers have concluded that any sustained usage of upload bandwidth (between 5 to 24 hours) will eventually result in a bandwidth cap. Users would not be able to use BitTorrent, FTP, or any server application without eventually getting capped. This can be avoided by setting a max upload speed of 10-15 kB/s, for BitTorrent users this effectively means you can seed, but only by a very limited amount (and stopping the torrent after finishing). One could indefinitely seed a torrent at 10 kB/s and never get capped. This would essentially exclude an Optimum Online customer from utilizing video conferencing or anything else that would be sending large amounts of data over a "high speed" connection that the customer is already paying for. Cablevision states that this is in accordance to a clause in their user agreement, where they may "use whatever means necessary to ensure the security and stability of their network". The upload capping seems to affect nodes that are crowded, as some users have never experienced an upload cap despite the fact they upload at max constantly.

Capping reduced a user's bandwidth from 15Mbit/s–2 Mbit/s (1920 kB/s–256 kB/s) to around 4.5 Mbit/s–140 kbit/s (576 kB/s–17 kB/s). The impact of the download speed reduction is caused by there not being enough upload bandwidth to send the amount of TCP acknowledgment packets needed to sustain a 15 Mbit/s download, a limitation of TCP, the reduction in download speed is not caused by a cap in the cable modem profile like the reduction in upload speed, but a side effect of TCP not having enough upload bandwidth because of the upload cap. After being throttled, there is no notification by Optimum Online other than reduced bandwidth performance. The customer must call Optimum Online to find out what has happened. Only then does Optimum Online inform the customer of the cap and tells its customers that after the fourth incident of throttling, your service will be terminated permanently. However, some users have called and Optimum Online customer service representatives have claimed that capping does not exist except for those users running servers, and when they check your account, claim that the user has in fact not been capped. OOL users can download large quantities of data without being capped.

Cablevision has also stated that Optimum Online Boost members can also be capped, which many have claimed as odd because they advertise the service as allowing members to run a server on their connection. Capping of members on Optimum Online Boost is extremely rare compared to customers on the standard plan (15 Mbit/s-2 Mbit/s). It is suggested by online user communities and occasionally by Cablevision service representatives, for users who are capped on the standard plan to upgrade to the more expensive Boost plan to get uncapped, and to prevent/reduce the risk of future cappings. Under-the-hood, the Boost plan uses a separate pool of bandwidth from the standard plan, which may explain why it would be treated differently.

Cablevision, which also offers Business Class connections, which have identical speed tiers, prices and nearly identical feature sets, caps them in exactly the same way as residential accounts. All of the above applies to Business Class connections. Cablevision Business Class should not be confused with the business targeted Metro Ethernet/Fiber based Cablevision Lightpath service. It is much more expensive and is a dedicated connection with a service level agreement.

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