Cooperative Control: Part 2 February 22, 2010
Posted by Devin Akin in : Uncategorized , trackbackCentralized Management, Distributed Control, and Distributed Forwarding
In order to better appreciate the Aerohive Networks cooperative control architecture, it is important to understand the three major functional areas, or logical network planes, that can be used to describe how network architecture operates: the management plane, the control plane, and the data plane.
By comparing the logical network planes of the most common networking devices – such as routers and switches – with that of HiveAPs, you can see striking similarities.
For example:
- They all have the ability to use a centralized management platform for configuration, monitoring, and troubleshooting, and because the management platform itself is not in the data path, it can be taken offline without affecting the functionality of the network.
- Each class of network device implements a distributed control plane that uses control protocols (e.g. OSPF, spanning tree, etc.) to share information between devices that allows them to coordinate with each other to ensure the network functions properly and continuously adapts to changes. With this knowledge of network state provided by the distributed control plane, each individual device is then able to implement a distributed data plane allowing each one to quickly make decisions on how traffic should be processed and forwarded using the optimal path.
This architecture has proven to be the winning architecture for switched and routed networks for many years because it is scalable, high performance, and resilient while still allowing for central management. As an example, the Internet uses this architecture.
Many enterprise WLANs today are implemented with a centralized controller-based architecture that breaks from this proven network architecture by centralizing the control plane and data plane in a controller hardware platform, which compromises scalability and resilience.
Aerohive’s cooperative control architecture is the first architecture to bring these proven network benefits to WLANs. The following chart shows the architectural parallels between cooperative control and the proven architecture used in switched and routed networks.
Extending the proven architecture used in switched and routed infrastructures to WLANs through the use of distributed control and data planes is especially important as enterprises require greater levels of availability, increased performance with 802.11n, and seek to improve productivity in their regional and branch offices. Distributing the control and data planes (e.g., removing controllers) eliminates single points of failure and performance bottlenecks from the entire wireless network, allowing the remote site deployment to be as simple and as functional as the campus deployment.
Key Concepts and Naming Conventions
The diagram below shows that HiveAPs have different roles which are automatically designated based on how they are connected to the network. The following is a list of key terms used to describe the Aerohive Networks cooperative control architecture:
- HiveAP®: The product brand name for Aerohive’s CC-AP (Cooperative Control Access Point). HiveAPs coordinate with each other using cooperative control protocols to provide critical functions including seamless mobility, automatic radio resource management (RRM), policy-based security, and best-path forwarding.
- HiveOS®: The firmware developed by Aerohive Networks that runs on HiveAPs.
- HiveManager®: A centralized wireless network management system (WNMS) that enables sophisticated identity-based policy management, simplistic device configuration, HiveOS updates, and monitoring and troubleshooting of HiveAPs within a cooperative control WLAN infrastructure. HiveManager is available as an appliance, a virtual appliance, or a SaaS offering called HiveManager Online™.
- Hive: A Hive is a group of HiveAPs that share a common name and secret key that permit them to securely communicate with each other using cooperative control protocols. Within a Hive, clients can seamlessly roam among HiveAPs across layer 2 and layer 3 boundaries, while preserving their security state, QoS settings, IP settings, and data connections.
- GuestManager™: A guest management platform that provides a simple web interface for allowing administrators, such as receptionists or lobby ambassadors, to create temporary user accounts that provide guests with access to the wireless network.
- Wired Backhaul Link: An Ethernet connection from a HiveAP to the primary wired network, typically called the distribution system (DS) in wireless standards, which is used to bridge traffic between the wireless and wired LANs.
- Wireless Backhaul Link: Wireless connections between HiveAPs that are used to create a wireless mesh and to provide wireless connections that transport primarily control and data traffic.
- Bridge Link: An Ethernet connection from a HiveAP that allows a wired device or network segment to be bridged over the WLAN onto the primary wired LAN.
- Wireless Access Link: The wireless connection between a wireless client and a HiveAP.
- Portal: A HiveAP that is directly connected to the wired LAN via Ethernet that provides default MAC routes to mesh points within the Hive. This role is dynamically chosen. If the wired link is unplugged, then the HiveAP can dynamically become a mesh point.
- Mesh Point: A HiveAP that is connected to the Hive via wireless backhaul links and does not use a wired link for backhaul. This role is also dynamically chosen. If a wired link is plugged in, the HiveAP dynamically becomes a portal, if permitted by the configuration.
- Cooperative Control Signaling: The control-plane communication between HiveAPs using Cooperative Control Protocols
Diagram 2. Aerohive Networks Naming Conventions
Comments»
Thanks for the quick overview and terminology of Aerohive components. Looking forward to the next in the series!