The document provides an overview of the Milan Internet eXchange (MIX) including: - MIX was founded in 2000 and is now an internationally recognized internet exchange point. - It is located in via Caldera in Milan where many operators were already interconnected, providing a critical mass. - MIX operates an on-site datacenter with over 800 sqm of space and infrastructure to support over 1800 devices and 3000 fiber connections. - Traffic has grown significantly over time, reaching peaks over 2.38 Tbit/s, and is impacted by special events like sporting matches. - MIX interconnects many autonomous systems including ISPs, cloud providers, content delivery networks, and more.

1. Milan Internet eXchange
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2. You’ve already been (t)here
on-line
shopping
software
update
…without even realising it
on-line gaming
social network
streaming

3. Where are we

4. The ‘campus’ of via Caldera

5. Why Caldera? Why MIX?
• Early ‘90: Unisource is selling interconnection
services (towards Europe and USA) to Italian
operators
• 1996: a first experimental mix is born, while
the critical mass of operators in via Caldera
continues to grow
• 2000: 28 charter members officially found
MIX s.r.l.
• Today: an internationally well-known node,
with thousands of active links

6. A name indicates what we seek.
An address indicates where it is.
A route indicates how to get there.
Jon Postel
RFC 791
1981

7. IPv4/IPv6 addresses
• IPv4, 32 bits, ~4 billion addresses
• IPv6, 128 bits, a sh*tload of them
‣ We rarely have to think about them anyway
How are addresses managed?
Where does mine come from?
Have you ever wondered…

8. IP address management
1. A central body (IANA) manages the whole addressing space
2. IANA assigns “blocks” to the various continents
3. A special Registry (Regional Internet Registry - RIR) assigns smaller
blocks to the operators within the continent
4. Every operator manages the assigned block autonomously

9. IP address management

10. IP addresses management
RIR
(Regional Internet Registry)
LIR
(Local Internet Registry)
217.0.0.0 /8
2001:1a00: /23
217.29.72.0 /21
2001:1ac0: /32

11. Autonomous
System
• Indicates a “family” of routers and networks
• Essential parameter for traffic exchange over the Internet
• Unique number
• Assigned by the RIPE NCC (or equivalent RIR)
185.1.224.0 / 24
217.29.72.0 / 21
2001:1ac0:: /48

12. www.ripe.net

13. IPv4 depletion
• There are basically no more IPv4
addresses available
• New phenomena:
‣ limited assignments
‣ reclaim unused space
‣ IPv4 marketplace
• No catastrophes, just work on IPv6
https://labs.ripe.net/Members/wilhelm/so-long-last-8-and-thanks-for-all-the-allocations
April 17th 2018
October 2nd 2019
Last /22 within the last /8 is assigned
Last contiguous /22 within the
recovered space is assigned
November 25th 2019
Last /22-equivalent is assigned
Now Waiting list for a /24

14. IPv4 depletion
• There are basically no more IPv4
addresses available
• New phenomena:
‣ limited assignments
‣ reclaim unused space
‣ IPv4 marketplace
• No catastrophes, just work on IPv6
https://labs.ripe.net/Members/wilhelm/so-long-last-8-and-thanks-for-all-the-allocations
April 17th 2018
October 2nd 2019
Last /22 within the last /8 is assigned
Last contiguous /22 within the
recovered space is assigned
November 25th 2019
Last /22-equivalent is assigned
Now Waiting list for a /24
At its meeting on 21 April 2023,
the RIPE NCC Executive Board
resolved to suspend the ability
of RIPE NCC members to submit
new applications to the IPv4
waiting list until further notice.

15. Interconnections
AS 12
AS 23
AS 34
AS 50
AS 20
AS 10
AS 70
AS 60
2
N x (N -1)
AS 40
AS 30
23.15.10.0 / 23
7.12.22.0 / 24
2002:a61f:c001::/48
203.116.10.0 / 23
94.38.224.0 / 19
2001:1ac0::/48

16. AS 34
AS 50
AS 20
AS 30
AS 40
AS 10
AS 70
AS 60
AS 12
AS 23
Peering

17. AS 10
AS 40 AS 60
AS 30
AS 20
AS 50
217.29.66.2 217.29.66.48
217.29.66.10
217.29.66.64
217.29.66.55
217.29.66.92
Ethernet LAN
Internet eXchange Point
property
of MIX
property
of MIX
members

18. AS 10
AS 40 AS 60
AS 30
AS 20
AS 50
217.29.66.2 217.29.66.48
217.29.66.10
217.29.66.64
217.29.66.55
217.29.66.92
Ethernet LAN
Internet eXchange Point
property
of MIX
property
of MIX
members

19. ISP Carrier
Cloud provider Content provider
CDN
Networks connected to MIX

20. AS 34
AS 50
AS 20
AS 30
AS 40
AS 10
AS 70
AS 60
AS 12
AS 23
Examples of peering

21. AS 34
AS 50
AS 20
AS 30
AS 40
AS 10
AS 70
AS 60
AS 12
AS 23
Examples of peering

22. AS 34
AS 50
AS 20
AS 30
AS 40
AS 10
AS 70
AS 60
AS 12
AS 23
Examples of peering

23. AS 34
AS 50
AS 20
AS 30
AS 40
AS 10
AS 70
AS 60
AS 12
AS 23
Examples of peering

24. Border Gateway Protocol
AS 100
AS 50
BGP
neighbors
(border router)
TCP session
Dialog between Autonomous Systems
50.49.18.0 / 24
50.49.19.0 / 24
2001:D50:: / 32
100.95.0.0 / 16
100.1.112.0 / 20
100.75.12.0 / 21
100.44.20.0 / 21
2001:100:: / 32
RFC 4271

25. Scale model
AS 50 AS 100
AS 25
AS 75
50.49.18.0 / 24
50.49.19.0 / 24
25.49.20.0 / 24
25.49.21.0 / 24
75.96.10.0 / 23
75.52.12.0 / 23
100.1.112.0 / 20
100.75.12.0 / 21
2002:75B::/ 32
2001:D50:: / 32
2002:25C:: / 32
100.44.20.0 / 21
100.95.0.0 / 16
2001:100::/32

26. Scale model
AS 50 AS 100
AS 25
AS 75
50.49.18.0 / 24
50.49.19.0 / 24
25.49.20.0 / 24
25.49.21.0 / 24
75.96.10.0 / 23
75.52.12.0 / 23
100.1.112.0 / 20
100.75.12.0 / 21
2002:75B::/ 32
2001:D50:: / 32
2002:25C:: / 32
100.44.20.0 / 21
100.95.0.0 / 16
2001:100::/32
AS 60
60.15.10.0 / 23
60.12.22.0 / 24
2001:60F::/32
100.1.112.0 / 20
100.75.12.0 / 21
100.44.20.0 / 21
100.95.0.0 / 16
2001:100:: / 32
100.1.112.0 / 20
100.75.12.0 / 21
100.44.20.0 / 21
100.95.0.0 / 16
2001:100:: / 32
50.49.18.0 / 24
50.49.19.0 / 24
25.49.20.0 / 24
25.49.21.0 / 24
2001:D50:: / 32
2002:25C:: / 32
50.49.18.0 / 24
50.49.19.0 / 24
25.49.20.0 / 24
25.49.21.0 / 24
2001:D50:: / 32
2002:25C:: / 32
75.96.10.0 / 23
75.52.12.0 / 23
2002:75B:: / 32
75.96.10.0 / 23
75.52.12.0 / 23
2002:75B:: / 32

27. When things go wrong…
YouTube & Pakistan Telecom,
a case of hijacking
Twitter & RTComm
https://www.youtube.com/watch?v=IzLPKuAOe50

28. www.manrs.org
(very) Useful resources
rpki.readthedocs.io
RPKI
Resource Public Key
Infrastructure Autonomous System
Provider Authorization
ASPA
bgpfilterguide.nlnog.net
ITalian Network
Operators Group
www.itnog.it
www.peeringdb.com

29. Traffic stats
10000+ TByte
every day
~
Peak traffic: 2.38 Tbit/s

30. Peak traffic progression

31. Connected interfaces (%)
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
0% 20% 40% 60% 80% 100%
Fast Ethernet 1 Gb 10 Gb 100 Gb

32. Special events
Italy - Germany
Italy - England
Italy - Spain

33. Italy - England
Italy - Costarica
Italy - Uruguay
Special events

34. UEFA Championship 2016
Italy - Germany

35. Inter
Sassuolo
Torino
Juventus
Juventus
Roma
Lazio
Roma
Effect
Since 2018…

36. New traffic records

37. 13 February 2022 - Atalanta - Juventus
New traffic records
19 September 2021 - Juventus - Milan 29 September 2021 - Juventus - Chelsea
17 October 2021 - Juventus - Roma
15 March 2023 - Napoli - Eintracht

38. CDNs
vs
ISPs

39. CDNs
vs
social network

40. MIX datacenter
• Fairly unique among IXPs
• ~800 sqm space
• 30 cm raised floor
• 20 cooling units
• Independent electrical distributions
• several km of cabling
• 1800+ devices installed
• 3000+ fiber interconnections

41. 2016
2021
Phase 1
Q4 2016
Datacenter 2
Phase 2
Q2 2021
Datacenter evolution
Datacenter 1

46. Outside Caldera Cornaredo (MI)
Milano
Siziano (PV)
Carini (PA)
Ponte S. Pietro (BG)
2010-2011
Equinix ML2
Irideos
2016
Data4
Supernap
2017
OHM
2018
Aruba
2022
Equinix ML5
Lepida
Bologna
Milano Caldera

48. OHM - Open Hub Med
http://www.submarinecablemap.com

49. Grazie!
@MIX_exchange
MIX s.r.l.
@mixexchange
MIX S.r.l.