QoS enabled WiFi MAC layer processing as an example of a NFV service

Abstract

The Configuration and Management of large WLAN deployments is a challenge and available tools to ease such deployments and introduce new services are either commercial or very inflexible. In this paper, we present a different approach to such challenges called QoS enabled CloudMAC, which is to the best of our knowledge the first step towards QoS enabled WiFi MAC layer processing as an example of Network Function Virtualization. By moving the MAC layer processing to the cloud and integrating our architecture with QoS aware OpenFlow deployment, a software defined networking approach, we achieve a new level of flexibility, control and reconfigurability. CloudMAC Access Points (AP) just forward MAC layer frames towards a set of VMs (Virtual Access Points-VAP) that are responsible for processing MAC layer data and management frames (such as beacons, probe requests, etc). We have extended the SDN that connects the VAPs with the physical APs to support different packet prioritisation strategies such as HTB, SFQ, or FQ CoDel. Our SDN controller is based on OpenDaylight which creates layer 2 forwarding rules that effectively prioritise CloudMAC traffic over legacy traffic. Our evaluation in a real testbed shows that packet prioritization strategies, especially FQ CoDel, lead to good throughput and low latency for CloudMAC traffic while at the same time maintaining low latency for background traffic.

HTBQueue: A Hierarchical Token Bucket Implementation for the OMNeT++/INET Framework

“…As the implementation requires link-layer specific knowledge and a slight adjustment to the utilized interface module (see Section 4.3), currently, the HTBQueue module can be used only with the Point-to-Point (PPP) interface available within the INET framework. We use OMNeT++ version 5.5.1 5 and INET Framework version 4.2.0 6 . ○, the classifier classifies all incoming packets according to its filters.…”

“…The Hierarchical Token Bucket (HTB) algorithm is one of the most widely used mechanisms for rate limiting. Implemented in the Linux traffic control tool tc, it is used for network control in testbed setups for research experiments [1,2,3] or in general to enforce per-flow Quality of Service (QoS) policies [4,5,6]. HTB allows to classify various types of traffic into different queues, according to properties such as the service type or IP address.…”

Next generation IEEE 802.11 Wireless Local Area Networks: Current status, future directions and open challenges

“…11. It has been extended in [190] to support QoS management and in [191] to support flexible MAC management frame prioritisation based on IEEE 802.11.…”

“…ODIN [186] 9 and has been extended in [188] to support QoS management and in [189] to support flexible MAC management frame prioritisation based on 802.11. A system based on OpenFlow has been recently proposed in [190] to allow the station to be associated with multiple APs simultaneously and to switch between APs with low overhead.…”

“…Similar to ODIN, CLOUD-MAC implements a Split-MAC approach but in addition enables the processing of WLAN MAC layer frames within a co-located Cloud using so-called Virtual APs (VAPs). 9 and has been extended in [188] to support QoS management and in [189] to support flexible MAC management frame prioritisation based on 802.11. A system based on OpenFlow has been recently proposed in [190] to allow the station to be associated with multiple APs simultaneously and to switch between APs with low overhead.…”