http://blog.multipath-tcp.org/blog/html/2015/07/24/korea.html
In September 2013, Apple surprised the networking community byenabling Multipath TCP on all iOS devices . The main motivation forthis deployment was to support Apple’s voice recognition applicationand enable it to work seamlessly over both WiFi and cellular networks.Multipath TCP is a good match for this application, but it can also be usedfor other use cases.
At IETF‘93 in Prague, SungHoon Seoprovided several very interesting details of the Gigapath commercialservice that is now sold by KT. This service enables smartphoneusers to reach bandwidth of up to 1 Gbps on existing smartphones. Thisis probably the fastest commercially deployed mobile network. They achieve thishigh bandwidth by combining both fast LTE (with carrier aggregation) andfast WiFi networks on Multipath TCP enabled smartphones. Atthis stage, only the Samsung Galaxy S6 and Galaxy S6 Edge smartphones supportthe Gigapath service, but KT is working with other vendors to addMultipath TCP on their smartphones. Measurements presented atthe MPTCP Working Group meeting revealed that current smartphones areable to reach throughputs of about 800 Mbps out of a theoreticalmaximum of 1.17 Gbps.
What is more impressive is how the system has been implemented and howthe users can benefit from it. The figure below, extractedfrom SungHoon Seo’spresentation provides the general architecture of theGIGA Path system.
On the client side, the smartphones include the open-source Multipath TCP implementation in the Linux kernel. Samsung reused release 0.89.4 andbackported it in their Android kernel. The full source code of theirMultipath TCP kernel is availableonline
Enabling Multipath TCP on the smartphone is the first step indeploying it. However, this is not sufficient since there are veryfew servers that support Multipath TCP today. To enable theirusers to benefit from Multipath TCP for all the applications that theyuse, KT has opted for a SOCKSv5 proxy. This proxy is running on x86servers using release0.89.5 of the open-source MultipathTCP implementation in the Linux kernel.During the presentation, SungHoon Seo mentioned that despite the recentrollout of the service, there were already 5,500 active users onthe SOCKS proxy the last time he checked. Thanks to this proxy, thesubscribes of the Giga Path service in Korea can benefit from MultipathTCP with all the TCP-based applications that they use.
At the end of KT’s presentation, another network engineer mentioned thathe would come back to his management and propose a similar approachto deploy Multipath TCP in his network. We can thus expect otherlarge scale deployments in the coming months.