2. Network management Reinhard Laroy BIPT European Parliament - 27 February 2012

3. Telecommunication network  All kinds of devices (pc, mobile, routers, server, …) randomly connected through transmission media  Sending data in packets to each other without setting up a permanent connection (e.g. postal services)  Routers forward data to the right destination through mechanisms that try to avoid network congestion Source Destination Core network router Connection data Source: UGent - IBCN

4. Networking dimensioning  The dimensioning is based on statistical models and overbooking to make the business case viable.  With overbooking the aggregation network (or core network) has a lower capacity than the sum of all foreseen capacities at the edge of the network 3 Link 100 Mbps Subscriber 1 Subscriber 2 Subscriber 3 Subscriber 24 … Offer 10 Mbps 240% overbooking Sum = 240 Mbps

5. Networking dimensioning  Compromise between the risk of traffic congestion and the necessary infrastructure investissements to guarantee the bandwidth while avoiding an underutilisation of the material  Linked to the usage profile of the subscriber 4 Congestion risk 1 / overbooking factor Necessary equipment

6. Traffic control  Network traffic control necessitates the control of the load on the different network routes:  The capacity is shared between different subscribers  The use of capacity peaks and/or evolves depending on the time of day. 5

7. Traffic control  Data packets are stored in buffer queue before processing by router and further forwarding over the network  If too many packets arrive, the queue will get full  packets will be lost  When the sender’s equipment doesn’t receive acknowledgements of certain packets, the packet is sent again and the speed is slowed down  After a while the sender’s equipment tries to increase the speed again  This speed mechanism is independent of content or application. Sender Destination Core network router Connection data Source: UGent - IBCN A buffer queue before each router and at the end points

8. Internet experience  Relevant parameters  bitrate or throughput (the amount of data transmitted in a unit of time)  delay  jitter (time variation of the average delay)  packet loss ratio  Constraints in the service provision for real time applications 7

9. Best effort is the general principle  The internet in principle is a best effort service because the bandwidth is limited (e.g. cables, equipment)  All internet users obtain a best effort service:  unspecified variable bit rate  unspecified delivery time  depending on the current traffic load 8

10. Quality of Service is the exception  However, certain traffic needs priority  Emergency calls  Voice calls and broadcasting are very sensible to packet loss and packet delays: the signal needs to be reproduced without distortion, noise, echo & loss of signal.  « cloud computing »  business applications 9

11. Adaptation of service  Each device, its quality  Each device needs a different quality of transmission  E.g. Smartphone screen doesn’t need same image quality  Different usage of each device  E.g. Browsing standard internet page on a mobile screen 10 Certain technologies, e.g. those related to mobile devices adapt the content and quality based on the access method and the available bandwidth

12. Traffic management  Maintain network stability  automatic traffic redirection in case of outage  congestion management  Prioritisation for certain types of data  Guaranteed network capacity for specific users  Legal intervention  Blocking sites with illegal content  Authentication of customers  Blocking of viruses and external attacks  E.g. Denial of Service attack  Block or degrade certain content 11

13. Conclusion  Congestion control is essential  Traffic differentiation has been in the network design all the time  A sensible level of (legitimate) traffic differentiation must be allowed for network management purposes 12

14. MERCI POUR VOTRE ATTENTION Confidentiel IBPT 13 worldBlack.png Thank you for your attention © BIPT 2012 - Reinhard Laroy – Reinhard.Laroy@BIPT.be Internet Map ChrisHarrison.net