Publication Date: 2010-Jun-22
Nokia Siemens Networks Idea: Thomas Hiestand
The following publication and the basic idea described in it are related to telecommunication systems and their control plane infrastructure.
More and more telecom applications appear request- ing for high availability of controller functionality within telecommunication equipment. This means in most of the cases: redundant controller structures as well as redundant communication infrastructure.
There are proprietary as well as standard approaches available to meet these requirements - but these solu- tions have some drawbacks. The existing approaches cause significant cost impacts.
Additional existing legacy equipment may not benefit from the existing approaches in terms of redundancy. The focus of this publication is therefore to overcome these drawbacks.
Current telecommunication equipment especially for scalable equipment with a lot of pluggable physical units often is based on hierarchical physical control plane structures. This means there are hierarchical structures of control units, distributed physically with- in the equipment.
The equipment may consist of several physical units (shelves, racks etc.) containing the pluggable physical units. Nowadays, telecommunication equipment often
bases on IEEE802.3 Ethernet conform or Ethernet like links for interconnecting the controller instances. See Figure 1 for illustration.
For the new upcoming applications with request for high availability of controller functionality within tele- communication equipment in most cases redundant controller structures as well as redundant infrastruc- tures are required.
This may lead to the following requirements:
• Redundant access to peripheral instances by redun- dant controller.
• Protection vs. controller failure by redundant con- troller instance (maybe protection is shelf over- spanning).
• Redundant controller instances can be maintained (plugged/de-plugged) independent from each other (they keep impact on functionality of equipment low).
To fulfill redundancy requirements like that, there are several solutions (proprietary or standard based, like ATCA) available.
Figure 2 shows the infrastructure of a typical not re- dundant telecommunication equipment. For example the equipment, here called Netele- ment instance, consists of a physi- cal housing holding the periph- eral instances and one controller instance.
The peripheral instances may have specific functions, according to the Netelement instance functional- ity. For control plane purpose, the peripheral instance as well as the controller instance has some con- trol units (computing units).
The control units are connected in a point to point way using layer 2 switched Ethernet based links. In
Figure 1: Physical view of telecommunication equipment, shelf view
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this example (Figure 2) controller instance and switch instance a...