Switch Speed Limit Function prevents BT download speed

Vswitches are still commonly used. So I studied the rate limiting function of the network switch. I will share it with you here, hoping it will be useful to you. Traditional FTP and HTTP downloads use point-to-point methods. It specifies a server or server group. All Users download data from this server. As the number of users increases, the demand for servers and bandwidth also increases. When too many users download files from the server at the same time, the speed will be very slow.

BitTorrent is directly translated into Chinese as "Bit Torrent"), which completely subverts the traditional download method and can provide large-capacity file downloads. BT adopts a method similar to pyramid scheme. Each user, as the downloader, is also the uploader. This situation effectively utilizes the uplink bandwidth and avoids the bottleneck that traditional FTP users squeeze into the server to download the same file. The more people added to the download, the more people actually uploaded, and the faster other users downloaded. Some BT websites claim that "downloading a full 8-minute video in 8 minutes" is a bit exaggerated. unless its bandwidth speed is very satisfactory, it downloads content that exceeds 1g within 30 minutes, but it's not about things. The speed will be fast and the efficiency will be significantly improved. Once the BT is launched, it will be welcomed by the majority of users.

The emergence of BT has brought an unprecedented revolution to online downloads, along with some negative effects. First, for users themselves, BT uses a poor HASH algorithm, as a result, repeated read/write operations on the hard disk directly affect its life. In this regard, users can protect their hard disks by limiting the upstream traffic of BT during use. However, for the entire network, if multiple users use BT for download at the same time, it will occupy a large amount of network bandwidth, seriously affecting the normal operation of other users in the same network segment. In a metaphor, if you travel on a highway, if your speed exceeds 200 yards, it will affect the normal operation of other users. Similarly, for other users, you may send an email as if you were using a dial-up call to access the Internet.

For the two popular access methods LAN and ADSL, when using the btsoftware, because ADSL is an exclusive bandwidth, users on each port enjoy only their own bandwidth outlets, the outbound bandwidth is also relatively small, so BT does not have any impact on ADSL users. However, for LAN access, bandwidth is shared, which can lead to extreme reduction in the speed of other users. That is to say, if one user in a building uses BT, the bandwidth of other users may be affected. During the peak period, each user may only allocate dozens of K bandwidth. This poses a challenge for operators. To ensure the interests of other users, BT users must be restricted.

There are many methods to limit the speed of the BT switch. Currently, CCProxy is a commonly used proxy software. You can set it to limit the bandwidth of the client and its maximum number of connections, it can also be completely blocked-BT download is not allowed at all, that is, the port number commonly used by TCP users is limited to 6881 ~ 6889. Because the BT port can be changed, once the BT download port changes, you need to immediately check the new port and disable it. However, the software-based approach is prone to malicious user attacks, resulting in system instability. For hardware, the speed limit can be used to prevent BT's occupation of network bandwidth. The F-engine switch of beacon network can provide two speed limiting methods based on traffic and Port:

The first is port-based speed limit. This type of switch speed limit is directly configured on the port. For example, the speed limit at the egress of Port 1 is 2 MB, the total traffic sent from this port is limited to 2 MB. This speed limit is implemented on the access switch, and each port is connected to a user. In this way, even if the user uses the BT download tool, the download rate provided to him has been limited by the switch, even if BT opens more TCP connections, it will not affect the performance of the entire network and eliminate the impact of BT on the network. This is a mandatory speed limit method, the beacon network can also provide a higher speed limit based on the needs of operators.

Stream-based speed limit is usually used for aggregation layer switches. When a port is connected to multiple users or units, an ACL entry can be used to define a stream rule, this rule can be the user's IP address, MAC address, and VIANid, TCP/UDP port number, and QOS service type. For example, you can define a flow rule as a TCP port number rule, add the BT user's port number to this flow rule to limit the BT traffic in the network. This method is similar to that of CCProxy, but the difference is that, ccproxy completely blocks BT users' ports, while the beacon network switch restricts the BT traffic in the network, that is, the user can still use BT, but the speed is limited, the purpose is not to affect the normal use of other users. The speed limit based on the stream can achieve two-way restrictions, that is, the operator can not only limit the user download speed, but also can limit the upload speed, truly control the network traffic.

It is worth mentioning that the switch of the beacon network implements "batch configuration" on the network management ", it means that the operator's maintenance personnel do not have to spend a lot of time configuring the switch speed limit and other configurations for each vswitch, but only need to configure one of the vswitches, you can configure 100 switches at a time when you copy the parameter to another switch. This avoids repetitive work and improves the efficiency of maintenance personnel.

Vswitches have been around for decades since they were created. With the use of vswitches and the maintenance requirements of operators, new technologies have emerged and speed limits are no longer a new topic, vswitches in many companies can provide this function. However, due to the fact that the granularity is not small enough and the speed limit on the uplink speed is unstable, it is often unsatisfactory, the second generation switch of the beacon network can refine the speed limit to 64 Kbps, providing a stable two-way speed limit. In the stream-based speed limit, different rules of IP/TCP/UDP can be selected for speed limit, increase the switch speed limit technology to the application level, so that the traffic control in the network can be used freely. If the emergence of BT brings about a download revolution, the emergence of the Second Generation switch of beacon network will bring about another revolution of BT user control.