SANGFOR originally designed ‘byte cache’ is able to cut redundant data at maximum extent during data transferring to improve bandwidth quality.
When data pass through WAN Optimization appliance, it will be cut into data segments at 100-200B at the same time be allocated with a unique label (10B) to send to the peer end WAN Optimization appliance(storage data bases at both end of the WAN Optimization device are precisely matched ). In following transferring process, any data or file will be cut into data segments by WAN Optimization appliance and matched one by one with the current data segments. If match successfully, only the corresponding labels will be transferred the peer end WAN Optimization appliance and at the same time restore the labels into data segments. If match unsuccessful, both the data segment and label will be sent to the peer end WAN Optimization appliance to ensure the equality at each end of WAN Optimization appliance.
WAN Optimization appliance designates each segment a unique label, this label not only include corresponding data information but partial information of the neighbour data packet, in this caste, when a data packet loses, WAN Optimization appliance will restore the lost packet according to the label of neighbour data packet without re-transferring to improve transmission efficiency.
Byte cache has an ability to reduce data amount during transmission, such as: origin file is 10M at both sending end and receiving end, data amount may probably reduce to 100K after optimisation procedure by WAN Optimization appliance. It means user has extend his bandwidth logically by using WAN Optimization appliance while the actual bandwidth remains the same, but simultaneously the data amount has reduced to 1/10 even 1/100 compares to the original size which leads to the conclusion that the logical bandwidth has expand by 10-100 times. Not all the data can be optimised by byte cache in real network environment; data which can be optimised gets different effect as well. But user will experience bigger bandwidth throughput and much higher speed.