A brief presentation on the evolution of Multipath TCP and its ongoing commercial deployment.

1. Internet innovation with Multipath TCP
Olivier Bonaventure

2. Internet basics
Physical
Datalink
IP
TCP
Application
Physical
Datalink
IP
TCP
Application
Physical
Datalink
IP
Physical
Datalink

3. Phase 1 : Specify
1990 1995 2000 2005 2010 2015 2020
1994 : IP Next
Generation
(IPng)
IETF RFC1752
1998 : IP v6
IETF RFC2460

4. Phase 2 : Implement
1990 1995 2000 2005 2010 2015 2020
1994 : IP Next
Generation
(IPng)
IETF RFC1752
1998 : IP v6
IETF RFC2460
2000 : IPv6
FreeBSD 4.0
Linux 2.6
2001 : IPv6
Windows XP
2003 : IPv6
OSX 10.3 Panther

5. Phase 3 : Deploy
1990 1995 2000 2005 2010 2015 2020
1994 : IP Next
Generation
(IPng)
IETF RFC1752
1998 : IP v6
IETF RFC2460
2000 : IPv6
FreeBSD 4.0
Linux 2.6
2001 : IPv6
Windows XP
2003 : IPv6
OSX 10.3 Panther
2008 DNS
root over IP v6

6. The origins of TCP
Source : http://spectrum.ieee.org/computing/software/the-strange-birth-and-long-life-of-unix

7. The TCP bytestream model
Client ServerABCDEF...111232
0988989 ... XYZZ
IP:1.2.3.4 IP:4.5.6.7

8. Endhosts have evolved
Mobile devices have multiple wireless interfaces

9. User expectations

10. What technology provides today
3G celltower
IP 1.2.3.4

11. What technology provides today
3G celltower
When IP addresses change TCP connections
have to be re-established !
IP 1.2.3.4
IP 5.6.7.8

12. Multipath TCP : Specify
2005 2010 2015 2020
2008 : Trilogy
Project starts
March 2009
IETF WG created
Jan. 2013
RFC6824 published
March 2011
RFC6182 published

13. The new bytestream model
16
Client ServerABCDEF...111232
0988989 ... XYZZ
IP:1.2.3.4 IP:4.5.6.7
IP:2.3.4.5 IP:6.7.8.9
BBCCDD AA

14. Multipath TCP : Design objectives
• Multipath TCP is an evolution of TCP
• Design objectives
– Support unmodified applications
– Work over today’s networks (IPv4 and IPv6)
– Works in all networks where regular TCP works

15. Architectural principles
Physical
Datalink
Network
Transport
Application
Multipath TCPMultipath TCP
TCP1TCP1
socketsocket
TCP2TCP2 TCPnTCPn...
Application
A. Ford, C. Raiciu, M. Handley, S. Barre, and J. Iyengar, “Architectural guidelines for Multipath
TCP development", RFC6182 2011.

16. Multipath TCP Data transfer
• Two levels of sequence numbers
Multipath TCPMultipath TCP
TCP1TCP1
socketsocket
TCP2TCP2
Multipath TCPMultipath TCP
TCP1TCP1
socketsocket
TCP2TCP2
ABCDEF
Data sequence #
TCP1 sequence #
TCP2 sequence #

17. Multipath TCP : Implement
2005 2010 2015 2020
Dec. 2009
First prototype
MPTCP on Linux
Dec. 2010
MPTCP on N900
smartphone
Sept. 2013
MPTCP iOS
Mar. 2013
MPTCP
FreeBSD
July 2015
MPTCP
Solaris

18. Multipath TCP : Deploy
• Low-latency for Siri
2005 2010 2015 2020
Sept. 2013
Siri uses MPTCP
WiFi
3G/LTE
Voice samples
Voice samples

19. Multipath TCP : Deploy
2005 2010 2015 2020
July 2015
KT uses MPTCP
WiFi
4G/LTE
Multipath TCP Regular TCP
SOCKS

20. Multipath TCP : Deploy
2005 2010 2015 2020
2016
Hybrid Access Networks
DSL
4G/LTE
Multipath TCP Regular TCP
Hybrid Access
Gateway
TCP
TCP

21. • Multipath TCP has brought innovation in the ossified
Internet transport layer
– Our open-source implementation played key role
• Confirmed to IETF that the design was correct
• Enabled commercial deployment
– Smartphones with Apple, LG, Samsung, …
– Link bonding with Tessares, OVH, Line Factory, Watchy, …
• Ongoing research with network protocols
– IPv6 Segment Routing
– Fibbing