719 research outputs found
SPIDER: Fault Resilient SDN Pipeline with Recovery Delay Guarantees
When dealing with node or link failures in Software Defined Networking (SDN),
the network capability to establish an alternative path depends on controller
reachability and on the round trip times (RTTs) between controller and involved
switches. Moreover, current SDN data plane abstractions for failure detection
(e.g. OpenFlow "Fast-failover") do not allow programmers to tweak switches'
detection mechanism, thus leaving SDN operators still relying on proprietary
management interfaces (when available) to achieve guaranteed detection and
recovery delays. We propose SPIDER, an OpenFlow-like pipeline design that
provides i) a detection mechanism based on switches' periodic link probing and
ii) fast reroute of traffic flows even in case of distant failures, regardless
of controller availability. SPIDER can be implemented using stateful data plane
abstractions such as OpenState or Open vSwitch, and it offers guaranteed short
(i.e. ms) failure detection and recovery delays, with a configurable trade off
between overhead and failover responsiveness. We present here the SPIDER
pipeline design, behavioral model, and analysis on flow tables' memory impact.
We also implemented and experimentally validated SPIDER using OpenState (an
OpenFlow 1.3 extension for stateful packet processing), showing numerical
results on its performance in terms of recovery latency and packet losses.Comment: 8 page
Merlin: A Language for Provisioning Network Resources
This paper presents Merlin, a new framework for managing resources in
software-defined networks. With Merlin, administrators express high-level
policies using programs in a declarative language. The language includes
logical predicates to identify sets of packets, regular expressions to encode
forwarding paths, and arithmetic formulas to specify bandwidth constraints. The
Merlin compiler uses a combination of advanced techniques to translate these
policies into code that can be executed on network elements including a
constraint solver that allocates bandwidth using parameterizable heuristics. To
facilitate dynamic adaptation, Merlin provides mechanisms for delegating
control of sub-policies and for verifying that modifications made to
sub-policies do not violate global constraints. Experiments demonstrate the
expressiveness and scalability of Merlin on real-world topologies and
applications. Overall, Merlin simplifies network administration by providing
high-level abstractions for specifying network policies and scalable
infrastructure for enforcing them
ICONA: Inter Cluster ONOS Network Application
Several Network Operating Systems (NOS) have been proposed in the last few
years for Software Defined Networks; however, a few of them are currently
offering the resiliency, scalability and high availability required for
production environments. Open Networking Operating System (ONOS) is an open
source NOS, designed to be reliable and to scale up to thousands of managed
devices. It supports multiple concurrent instances (a cluster of controllers)
with distributed data stores. A tight requirement of ONOS is that all instances
must be close enough to have negligible communication delays, which means they
are typically installed within a single datacenter or a LAN network. However in
certain wide area network scenarios, this constraint may limit the speed of
responsiveness of the controller toward network events like failures or
congested links, an important requirement from the point of view of a Service
Provider. This paper presents ICONA, a tool developed on top of ONOS and
designed in order to extend ONOS capability in network scenarios where there
are stringent requirements in term of control plane responsiveness. In
particular the paper describes the architecture behind ICONA and provides some
initial evaluation obtained on a preliminary version of the tool.Comment: Paper submitted to a conferenc
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