Programming the data path in network processor-based routers

Abstract

There is growing interest in network processor technologies capable of processing packets at line rates. Network processors are likely to be an integral part of next generation high-speed router and switch architectures, replacing the application-specific integrated circuits (ASICs) that are used in routers today. In this paper, we present the design, implementation and evaluation of NetBind, a high-performance, flexible and scalable binding tool for dynamically constructing data paths in network processor-based routers. The methodology that underpins NetBind balances the flexibility of network programmability against the need to process and forward packets at line speeds. To support the dynamic binding of components with the minimum addition of instructions in the critical path, NetBind modifies the machine language code of components at run time. To support fast data path composition, NetBind reduces the number of binding operations required for constructing data paths to a minimum set so that binding latencies are comparable with packet forwarding times. Data paths constructed using NetBind seamlessly share the resources of the same network processor. Resources are assigned during the binding process. We compare the performance of NetBind to the MicroACE system developed by Intel and show that NetBind provides better performance in comparison to MicroACE with smaller binding overhead. The NetBind source code described and evaluated in this paper is freely available on the Web (http://www.comet.columbia.edu/genesis/netbind) for experimentation.There has been a growing interest in network processor technologies [1-3] that can support softwarebased implementations of the critical path while processing packets at high speeds. Network processors employ multiple processing units to offer high packet-processing throughput. We believe that introducing programmability into network processor-based routers is an important area of research that has not been fully addressed as yet. The difficulty stems from the fact network processor-based routers need to forward minimum size packets at line rates and yet support modular and extensible data paths. Typically, the higher the line rate supported by a network processor-based router the smaller the set of instructions that can be executed in the critical path.Data path modularity and extensibility requires the dynamic binding between independently developed packet processing components. While code modularity and extensibility are supported by programming environments running in host processors (e.g. high-level programming language compilers and linkers), such capability cannot be easily offered in the network. Traditional techniques for realizing code binding (e.g. insertion of code stubs or indirection through function tables), introduce some overhead when applied to network processors in terms of additional instructions in the critical path. This overhead can be significant in some network processors. One solution to this problem is to optimize the code produced by a binding ...

Framework for supporting multi-service edge packet processing on network processors

“…Router Plugins [4] and PromethOS [26] have explored this issue on general purpose processors, while VERA [29] is focused on systems with a general purpose host processor coupled with processors on intelligent NICs or a network processor. NetBind [18] allows different pieces of machine code to be composed together efficiently on network processor systems using dynamic binding. However, none of these efforts focus on handling traffic fluctuations.…”

Processor Scheduler for Multi-Service Routers

“…For instance, researchers have observed that simply loading the instruction store of a processing core with the code for a new service on Intel R 's network processors takes of the order of a millisecond [21,9], while a packet can often be processed within a few microseconds (t sw t pkt ). Similarly, Qie et al [27] observe t sw to be twice t pkt in PCbased routers.…”

NetBind: a binding tool for constructing data paths in network processor-based routers

“…While virtual networks share resources, they do not necessarily use the same software for controlling those resources. Programmable virtual networks can be created by selecting customized protocols for transport, signaling, control and management and by binding their associated software components into the network infrastructure at run time [14]. …”

“…Second, registers can hold input arguments. Input arguments are passed dynamically into components when pipelines are created from an external source, (e.g., the control unit of a virtual router [14]). Each component can place its own arguments into input argument registers overwriting the input arguments of the previous component.…”

“…NetBind can be used to dynamically program a diverse set of data paths. For example, in [14] we show how Cellular IP [6] data paths can be composed for network processor-based radio routers. NetBind can create packet-processing pipelines through the dynamic binding of small pieces of machine language code.…”