One router buffer is a little bit bigger, do you know how much benefit it will bring? A little bit smaller, do you know how much sorrow it will bring?
When running high-speed, sometimes two cars slightly rub, will bring dozens of kilometers of congestion .... This is the global chain reaction caused by local accidents. The year before last, Shanghai Jia High-speed construction, demolition of the central green Belt, the removal of hard shoulder, the two lanes into three lanes, you can not underestimate this one lane, the role of the big.
For the network, when the packet on the cable, absolutely safe, absolutely full speed forward, the most dangerous is to reach the forwarding device, the inherent delay of the device processing packet caused by the packet must have the opportunity to be buffered, processing acceleration ratio must be corresponding to the buffer size, Increasing the buffer size at this point is similar to the freeway lane increase, the role of the big go. Regardless of the increase, there is a formula between the buffer size and the line bandwidth, and to be honest, TCP is a big help for this formula.
We know that UDP stateless without connection, lost and lost, no one knows, everything silently. So the forwarding device is not able to measure how much buffer is set. But TCP can help. TCP has a RTT, which is the time required for a packet to go back and forth, and after the timestamp is turned on, the measurement is accurate, so the buffer size setting of the forwarding device is related to this. In other words, the buffer must be able to hold a packet of TCP round-trip time, which can continue to reach how much? This is determined by the bandwidth. If the buffer size is less than this value, TCP will continue to drop packets once the internal queue is blocked or delayed. Therefore, the higher the speed of the link, the larger the buffer size, network bandwidth continues to improve today, how the device in the unit time buffer storage such a huge amount of data is a big problem. Of course, TCP discovery drops will spin down, then UDP?
In the final analysis, the determining factor of the buffer size of the forwarding device is the memory access efficiency, what kind of storage devices can meet the requirements now? A huge amount of data, directly to the expensive things to pass, regardless of parallelism, what is the artifact?
The Night is deep! Little birthday has passed, have a good time, I am also very happy!
Why the router buffer size is so important
