Title
dRMT: Disaggregated Programmable Switching
Abstract
We present dRMT (disaggregated Reconfigurable Match-Action Table), a new architecture for programmable switches. dRMT overcomes two important restrictions of RMT, the predominant pipeline-based architecture for programmable switches: (1) table memory is local to an RMT pipeline stage, implying that memory not used by one stage cannot be reclaimed by another, and (2) RMT is hardwired to always sequentially execute matches followed by actions as packets traverse pipeline stages. We show that these restrictions make it difficult to execute programs efficiently on RMT. dRMT resolves both issues by disaggregating the memory and compute resources of a programmable switch. Specifically, dRMT moves table memories out of pipeline stages and into a centralized pool that is accessible through a crossbar. In addition, dRMT replaces RMT's pipeline stages with a cluster of processors that can execute match and action operations in any order. We show how to schedule a P4 program on dRMT at compile time to guarantee deterministic throughput and latency. We also present a hardware design for dRMT and analyze its feasibility and chip area. Our results show that dRMT can run programs at line rate with fewer processors compared to RMT, and avoids performance cliffs when there are not enough processors to run a program at line rate. dRMT's hardware design incurs a modest increase in chip area relative to RMT, mainly due to the crossbar.
Year
DOI
Venue
2017
10.1145/3098822.3098823
SIGCOMM
Keywords
Field
DocType
Programmable switching,packet processing,RMT,disagreggation
Computer science,Latency (engineering),Compile time,Network packet,Parallel computing,Chip,Packet processing,Throughput,Crossbar switch,Embedded system,Traverse
Conference
ISBN
Citations 
PageRank 
978-1-4503-4653-5
16
0.62
References 
Authors
6
12
Name
Order
Citations
PageRank
Sharad Chole1642.80
Andy Fingerhut2943.35
Sha Ma3559.30
Anirudh Sivaraman450528.19
Shay Vargaftik5476.22
Alon Berger6160.62
Gal Mendelson7173.36
Mohammad Alizadeh8148277.16
Shang-Tse Chuang919213.36
Isaac Keslassy1098672.83
Ariel Orda112595351.94
Tom Edsall122079.37