Shaun Fensom's presentation at the INCA Seminar 30/10/2013, explaining the concept and development of Digital Exchanges

1. Digital Exchanges

2. Aggregation point
To overcome path dependencies

3. Path dependence explains how the set of decisions
one faces for any given circumstance is limited by
the decisions one has made in the past, even though
past circumstances may no longer be relevant.
Positive feedback mechanisms like bandwagon and network
effects are at the origin of path-dependence.

4. A
B
C

5. Three path dependencies
Bandwidth aggregation for end users
Clustering of digital business
Backhaul and hosting for access
networks

6. Components
Space for businesses
Internal connectivity
Internet connectivity
Hosting space
Mutual governance
6

7. Another
DX
Hosting
Remote
IXP
Nearest
IXP
DX
Local access network
Local users
in DX
Local access network

8. 8

9. Bandwidth aggregation
Reduce cost of high quality access

10. Nearest
IXP
DX
Local users
in DX

11. Simple aggregation
• High-speed
connection to IXP
– Cost shared using DX
organisation
– Users access via
internal network
– Could use vouchers
• Simple rationale
– 10 x bandwidth, 2 x
cost
• Layer 2 (or WDM)
– Allowing multiple ISPs
– Shared “ownership”
of connection
11

12. Another
DX
Nearest
IXP
Remote
IXP
DF
Hosting
Local users
in DX
DX
Carrier
PoP

13. Clustering digital business
Creating a virtuous circle

14. 14

15. Attractive space
Good, flexible terms
Sense of
shared
ownership
High quality connectivity
Flexible hosting
Choice of service providers

16. Backhaul aggregation
Carrier neutral centre for new access
networks

17. End users
End users

18. Tier 1
ISP
Tier 1
ISP
Tier 1
ISP
Transit
Transit
ISP
IXP
ISP
Peering
End users

19. Another
DX
Hosting
Remote
IXP
Nearest
IXP
DX
Local access network
Local users
in DX
Local access network

20. Access network
Backhaul
Hub
Independent
Open access
Mutual ownership

21. Thank you
s.fensom@broadband.coop