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

2. 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
Destination
Source
Connection
data
router
Core network
Source: UGent - IBCN

3. 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
Subscriber 1
Offer 10 Mbps
Subscriber 2
Offer 10 Mbps
240%
overbooking
Subscriber 3
Offer 10 Mbps
Link 100 Mbps …
Subscriber 24
Offer 10 Mbps
Sum = 240 Mbps

4. 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
Congestion risk
Necessary equipment
1 / overbooking factor

5. 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.

6. Traffic control Destination Sender Connection Core network router
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.
Destination
Sender
Connection
data
router
Core network
A buffer queue before each router and at the end points
Source: UGent - IBCN

7. 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

8. 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

9. 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

10. 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
Certain technologies, e.g. those related to mobile devices adapt the content and quality based on the access method and the available bandwidth

11. 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

12. 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

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