The Missing Step in Transport Network Planning
InterComms talks to Mr. Károly Kara, Project Services Director of FlexiTon
The article in the Intercomms magazine
Download article as pdf
COMMUNICATION SERVICE PROVIDERS HAVE CONTINUOUS TRAFFIC AND TRANSPORT CHALLENGES. WE WILL SHOW HOW TO LINK LONG TERM STRATEGY TO DAY-TO-DAY ENGINEERING REALITY IN THIS ENVIRONMENT.
There is nothing new in saying that the pace of change in any communications network is increasing. However there are still a number of key questions:
- Do we have a good answer to the question how to link the long-term business and technology strategy to short-term planning and engineering reality?
- How to get meaningful planning results when a lot of data is missing or unreliable and on top of that there are many uncertainties in the demand predictions?
- “Time to market”, as one of the key requirements to be successful, is very well known. Do we really exploit all of our potential to respond to the fast changing demands?
- For a long time over-dimensioning has been the only means to ensure the capability to fulfil new demands very fast. Is over-dimensioning of the transmission/transport networks sustainable? Will these networks be technology and cost optimised in order to be more effective?
- In many cases there are well-thought out technology strategies as well as fine-tuned short-term planning and configuration processes. Are these two linked consistently or is the former’s output simply one of the inputs to the latter one?
Whenever these questions and concerns need to be addressed then the ARIADNE/NetAnalyst (medium term planning tool) is able to help to find the right answers, irrespective of the technologies used or equipment vendors involved.
Medium Term Planning in the Network Lifecycle
First let’s look at the role of planning in the network lifecycle. Strictly speaking network planning is about reasonable dimensioning and configuring network structure and resources according to quantitative and qualitative requirements, based on well-defined methodical algorithms. Medium term planning looks beyond the daily operative expansions and reconfigurations, at the same time it is much more specific than a long-term plan. In real life ARIADNE/NetAnalyst focuses on the next few month time horizon.
The planning process is well represented by the “analyse – design – optimise – manage (rollout) – confirm modifications (in the data warehouse) – analyse” cycle. Although this seems to be a sequential model, the reality is closer to a mesh process topology, as in many cases the previous cycle is not yet completed by the time new demand arises.
Planning Process with ARIADNE/NetAnalyst (Medium term Planner)
ARIADNE/NetAnalyst supports the planning cycle with potential loopbacks during the phases, which is required in most networks in real life. The main steps of planning with ARIADNE/NetAnalyst:
- Model creation: loading of existing network data, traffic data, building of modelled network specific data, setting of traffic, fill-rate and capacity parameters
- Running and evaluation of analysis cycles, reporting
- Saving and exporting of any network status
The planning process with ARIADNE/NetAnalyst is iterative and supports decision making in each step. ARIADNE/NetAnalyst does not aim to replace the creativity of the experienced network planners, on the contrary, ARIADNE/NetAnalyst supports the planning process so that the planners can create the optimal solution.
In practice the iterative managed processes:
- ARIADNE/NetAnalyst analyses and compares – The planner evaluates and makes decisions
- The planner specifies alternative designs – ARIADNE/NetAnalyst analyses, compares, optimises (within boundaries) - The planner evaluates and makes decisions
The iterative nature of these processes reduces significantly the time and effort needed for a medium term planning cycle.
ARIADNE in Medium Term Planning
Can network planning be fully automated intelligently? The answer is clearly: No. However ARIADNE/NetAnalyst can support engineers in focusing their attention on real engineering work by offloading the repetitive tasks and calculations. On top of that, modelling and visualisation of the network are key functionalities that support engineers to find the most innovative, optimal design, irrespective of the planned technologies (SDH, NGSDH, PDH, IP (explicit routed), IGP – OSPF, IS-IS, RIP, EIGRP,EGP–BGP, IP/MPLS, IP/MPLS TE, Ethernet, Carrier Class Ethernet, Carrier Ethernet Transport (PBT, PBB), WDM, MPLS/TP, OTN, NG WDM).
The basic principles of effective planning that ARIADNE/NetAnalyst is built on:
- Adaptation to the different levels of existing data (i.e. detail, accuracy, completeness)
- Flexible data model (unified, abstract modelling framework, which is required to cope with heterogeneous networks)
- Robust, theoretically well founded analytic and planning algorithms based on best engineering practices, matching the various levels of available network data
- Clear user interface, consistent, well-structured data and process visualisation
- Easy to manage iterative planning process
ARIADNE/NetAnalyst supports the medium term planning (dimensioning, expansion or reconfiguration) of any aggregate or backbone network according to several criteria (capacity, reliability and cost). ARIADNE/NetAnalyst is a comprehensive tool, which covers all key aspects of modern network planning:
- Any physical or virtual/logical node can be included in the planned network
- “Client” (mobile services, synchronisation network orDCN) and “Server” layers (wireless or wireline physical connections))
- Topologies: single or parallel routes, bus, star/tree, mesh or ring are possible to plan with various protection methods
- Detailed analysis, covering scalability, failure impact, availability, service quality (QoS)
- Includes service planning with or without capacity extensions, network consolidation and reorganization
Any communications network operator, managed services or optimisation service provider orOSSsystem integrator can benefit from the functionalities of ARIADNE/NetAnalyst.
ARIADNE/NetAnalyst is an effective tool in case of any rapidly changing communication network. Whether it is a carrier network serving large number of enterprise clients, or it is an LTE backhaul of a mobile operator, the benefits of ARIADNE/NetAnalyst prevail. The size of the network has no impact. ARIADNE/NetAnalyst is very useful in a relatively small city network, and it is as, or even more, effective on a multi-layered network with tens of thousands of nodes/links.
The example described below highlights the challenges and answers of a major expansion/transformation in a real network, which is an LTE backhaul network of a large area. ARIADNE/NetAnalyst supported the whole planning process from the definition phase.
In this LTE backhaul, according to the defined technology strategy, the transmission core had to meet the following criteria:
- Traffic is aggregated to IP/MPLS transmission core
- IP/MPLS logical topology is designed from scratch, IP/MPLS PE and P routers are interconnected by dark fibres
- Forwarding is based on IGP (OSPF) protocol
- Optical cable topology is based on realistic duct arrangements
- Dimensioning of required node and link capacities taking into account failure-free as well as single (cable, equipment and interface card) failures
In this network ARIADNE/NetAnalyst was used to:
- Define the number of layers: access, aggregate and backbone layers were defined as optimal solution
- Create a layered model network
- Design the architecture and calculate traffic data
- Estimate implementation cost
- Provide topology views, such as IP/MPLS logical topology, IP/MPLS site inner topologies, Optical Cable and Duct Topology
- Calculate availability and reliability predictions
- Predict the impact of failures in terms of:
- Analysis of failure impact
- Load taking into account on remaining links
- Comparing it with link loads in failure-free network state
There are numerous business benefits that ARIADNE/NetAnalyst can provide, some of them are easier to quantify, and some are more difficult to directly translate into financials.
“Time to market”, fast fulfilment of new capacity demands has been an important value element for long time. With the telecommunication equipment and their operation getting more affordable many communications network operators started to over-dimension their networks to be able to respond to new demands quickly. At the same time the fierce competition drives continuous cost reductions. These two competing requirements force CSPs to seek for the fine balance between spare capacity and cost. ARIADNE/NetAnalyst helps to find the balance with its capability to build scenarios fast, and also with reducing the time needed for a planning cycle.
Instant, advanced visualisations of planned scenarios, all layers, in the design phase provide a great help to find the optimum solution for the architecture changes.
There are many tools, mainlyOSSbased, that help to determine the quality, availability and reliability of an existing network. There are far less tools that do this in the planning phase. ARIADNE/NetAnalyst not only helps with availability and reliability predictions, it also calculates the impact of failure on other parts of the network (i.e. impact on other routes and services). This functionality can be used effectively to build contingency scenarios or determine availability for service level agreements.
ARIADNE/NetAnalyst is the result of the cooperation between FlexiTon and Budapest University of Technology and Economics. This brings together the best combination of the latest theoretical knowledge with abstract modelling coupled with long term international field experience.
Time to the market, efficiency, and cost optimisation are of basic importance in any communication network. ARIADNE/NetAnalyst is a flexible toolkit for experienced network planners to cope with these challenges in any vendor supplied networks.