1. mptcp proxies Mark Handley

2. MPTCP Mobility
3G celltower
Mobile client
Server

3. MPTCP Mobility
Mobile client
Server
Wifi
Wifi

4. MPTCP Mobility
Server
Mobile client
Wifi
Wifi

5. MPTCP Mobility
Server
Wifi
Mobile client
Wifi

6. MPTCP as a mobility solution
Short paper:
Scenario: want to use variable quality 3G and intermittently available WiFi hotspots.
Preliminary results show we can achieve better throughput, more robustness, and save battery power.

7. Need to be able to depend on MPTCP availability
Problem:
For the near future, most of the servers won’t support MPTCP.
Solution:
Perform MPTCP to a proxy.

8. MPTCP Mobility: Legacy Server
MPTCP Proxy
Mobile client
Server
MPTCP client sends SYN to proxy, indicating address of
final server. Proxy initiates connection to server.

9. MPTCP Mobility: Legacy Server
MPTCP Proxy
Server
New subflows are set up to the proxy, which load-balances
in the normal MPTCP manner.

10. MPTCP Mobility: MPTCP Server
MPTCP Proxy P
Mobile client
MP_CAPABLE
MP_CAPABLE
MPTCP
Server S

11. MPTCP Mobility: MPTCP Server
MPTCP Proxy P
Mobile client
MP_CAPABLE
ADD_ADDR: S
MP_CAPABLE
MPTCP
Server S
Proxy knows server is MP_CAPABLE. Sends ADD_ADDR to tell client.

12. MPTCP Mobility: MPTCP Server
MPTCP Proxy P
Mobile client
MPTCP
Server S
Client sets up new subflow direct to server.
Proxied path becomes backup - not used for data traffic

13. MPTCP Mobility : MPTCP Server
MPTCP Proxy P
MPTCP
Server S
New subflows go direct to server.

14. MPTCP Proxies Proxies are TCP-level relays - no application semantics.
Protocol implication:
Need to indicate (preferably in SYN) the address of the server the proxy should connect to.
No other change needed.
Issue: space in SYN.