MP-Cos: An efficient storage compression and optimization scheme of flow table for multi-protocol network scenarios

Various network protocols and technologies are complemented to accommodate diverse and indeterministic network services, and advances in programmable switches allow network administrators to develop these emerging protocols. However, the increasing demand for the number and length of match fields and the action types of diverse network protocols exacerbates the storage pressure on storage chips, such as Ternary Content Addressable Memory (TCAM), which significantly increases the implementation complexity. The existing flow table compression algorithms for the single protocol network scenario are not applicable to multi-protocol network scenario owing to two key issues: (1) the increase in match fields causes an increase in the storage width of the flow table rules, which puts pressure on the TCAM resource capacity and has a high implementation complexity; (2) the storage sharing of flow table between different protocols will cause semantic ambiguity between match fields, resulting in incorrect action matching. To support multi-protocol flow tables and improve hardware resource utilization, we propose MP-Cos, an efficient storage compression and optimization scheme that supports multi-protocol flow tables, and design a match field trimming algorithm based on statistical features to support the field splitting within a single protocol; We also design a dynamic protocol field mapping mechanism to optimize the field merging between different protocols. MP-Cos not only facilitates the sharing of flow table storage among different protocol fields but also addresses the serious resource storage consumption caused by the scale of flow tables in multi-protocol network scenarios.