A fluctuation between times of data-center networking peak usage and underutilization results in a graph with peaks and valleys …<\/p><\/div>\n
\u201cThe reason is,\u201d Bahl says, \u201cthe network itself is not able to adapt its global behavior intelligently to the changing requirements. Ideally, after high-priority indexes have been moved, the network would reconfigure itself to meet the traffic demands of other servers inside the data centers. With SDNs, by pulling out the control and making the switch simpler, the controller is able to look at all traffic demands globally and configure the switches to adapt the network behavior intelligently.<\/p>\n
\u201cLooking at pipe utilization, there are peaks and valleys. With SDNs, we fill the valleys with data from different sources inside the data center and fill up the pipe.\u201d<\/p>\n
![\"software-defined](\"https:\/\/www.microsoft.com\/en-us\/research\/wp-content\/uploads\/2016\/09\/software-defined-networking-approach.png\")
… but by using a software-defined networking approach, the valleys can be filled in with data from different data-center sources, greatly enhancing efficiency.<\/p><\/div>\n
The stakes are high.<\/p>\n
\u201cThere\u2019s data to be moved,\u201d Bahl states. \u201cOnce the data moves, the servers become free, and then they can be used for other jobs. If the data does not move fast enough, even though we have a big pipe, the servers stall. By making the pipe available to these stalled servers, we free them up to do other work, thus getting more efficiency out of the data center.<\/p>\n
\u201cWe will save a lot of money if we get this right. This is important because it will reduce the overall cost of operating data centers, which, in turn, will reduce the cost for everyone using the cloud.\u201d<\/p>\n
That, though, is not all. The approach taken by Varghese and his colleagues in the Forwarding Metamorphosis<\/em> paper could represent yet another sea change.<\/p>\nWithin a data center, a router performs two vital processes: packet forwarding and managing the dynamic tables that determine the forwarding address when a link changes. SDNs can enable changing the software that controls the building of the routing tables, providing more flexibility with the control plane. But the basic hardware portion of the router can\u2019t be changed.<\/p>\n
The forwarding mechanism, though, can.<\/p>\n
\u201cWe propose mechanisms to allow changing the forwarding<\/em>, in addition to changing the routing<\/em>, as SDN already allows,\u201d Varghese says. \u201cThat\u2019s really the big idea here.<\/p>\nChanging Packets on the Fly<\/h2>\n
\u201cThe \u2018forwarding metamorphosis\u2019 means we can actually change what is done to a packet as it travels through a router, which SDNs today cannot. SDNs only allow you to change the contents of tables, but not the actual forwarding process of a router. We change the way you could understand packets, the way you could allocate table entries among various functions of the router, and the way you could process a packet so that the same piece of hardware can be transformed from being an edge router to a core router to even what is called a bridge.\u201d<\/p>\n
For some time, researchers thought that network processors could provide the ability to provide additional flexibility with the packet-forwarding piece of the data-communications puzzle. But routers work at speeds much, much faster than the fastest network processor or field-programmable gate array. As Varghese explains, \u201cWe really need the power of raw hardware.\u201d<\/p>\n
That\u2019s not to say that such power cannot be combined with flexibility. He and his co-authors\u2014acclaimed researchers from Stanford University and circuit designers from Texas Instruments\u2014have constructed a mechanism that provides three flexibilities:<\/p>\n
\n- Flexible parser:<\/strong> If you want to add an additional field to a packet to fine-tune the forwarding process, you need to find a way to do so while using existing hardware. Parsers understand the meaning of such packet fields.<\/li>\n<\/ul>\n
\u201cWe built a flexible parser,\u201d Varghese says, \u201cwhere, in an operational network, you could say: \u2018I\u2019m changing this protocol. It uses these particular bits in the packet, and this is what they now mean.\u2019 We can do that without upgrading the hardware.\u201d<\/p>\n
\n- Flexible tables:<\/strong> Managing a router\u2019s forwarding tables can get complicated, particularly in determining how to allocate memory. The Forwarding Metamorphosis<\/em> paper explains how to build flexible memory than can be divided to address various uses\u2014again, without requiring new hardware.<\/li>\n
- Flexible actions:<\/strong> Many people have argued in recent years that the traditional Transmission Control Protocol could be improved greatly if congestion information could be appended to a packet. Not with fixed hardware, though. But the work by Varghese and his colleagues enables the ability to write arbitrary packet fields after the fact.<\/li>\n<\/ul>\n
Such work represents nothing less than a new frontier in networking.<\/p>\n
\u201cThis,\u201d Varghese says, \u201cis what SDNs should look like five years from now.\u201d<\/p>\n
The third SDN-related paper provides further evidence of Microsoft Research\u2019s intention to remain at the forefront of this exciting new opportunity.<\/p>\n
The new network architecture of SDNs creates a unique problem\u2014and opportunity\u2014 that the zUpdate<\/em> paper addresses. zUpdate eases network planning necessary to keep data-center networks running smoothly during software updates.<\/p>\n\u201cThis,\u201d Bahl says, \u201cis about how you update these switches and do so in a way that doesn\u2019t affect the smooth operation of the data center. You have to update them in a very systematic manner.\u201d<\/p>\n
Other SIGCOMM 2013 papers from Microsoft Research pertain to such concerns as load balancing at the cloud level, resource management for data-intensive cloud applications, anonymity networks, and near-field communication.<\/p>\n
\u201cCloud services are becoming very important, and we have to make them very efficient,\u201d Bahl concludes. \u201cAt Microsoft, we\u2019ve been working hard to make our data centers extremely efficient. We are doing this by focusing on the networking-infrastructure piece, both within our data centers and between our data centers.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
These are exciting times for networking researchers. New developments in data-center networking\u2014and the new efficiencies those advances offer\u2014are making this one of the hottest fields in computing. Major figures in networking and communications research gather in Hong Kong from August 12 to 16 for SIGCOMM 2013, the flagship annual conference of the Association for Computing […]<\/p>\n","protected":false},"author":39507,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"footnotes":""},"categories":[194476,194485],"tags":[211955,187191,211967,211964,211970,211952,211958,211961],"research-area":[13552,13547],"msr-region":[],"msr-event-type":[],"msr-locale":[268875],"msr-post-option":[],"msr-impact-theme":[],"msr-promo-type":[],"msr-podcast-series":[],"class_list":["post-287960","post","type-post","status-publish","format-standard","hentry","category-devices-and-hardware","category-networking","tag-association-for-computing-machinerys-special-interest-group-on-data-communications","tag-data-center-networking","tag-data-center-networking-peak-usage-and-underutilization","tag-network-switches","tag-pipe-utilization","tag-sigcomm-2013","tag-software-defined-networks-sdns","tag-web-scale-data","msr-research-area-hardware-devices","msr-research-area-systems-and-networking","msr-locale-en_us"],"msr_event_details":{"start":"","end":"","location":""},"podcast_url":"","podcast_episode":"","msr_research_lab":[199560,199561,199562,199565],"msr_impact_theme":[],"related-publications":[],"related-downloads":[],"related-videos":[],"related-academic-programs":[],"related-groups":[144899],"related-projects":[],"related-events":[],"related-researchers":[],"msr_type":"Post","byline":"","formattedDate":"August 12, 2013","formattedExcerpt":"These are exciting times for networking researchers. New developments in data-center networking\u2014and the new efficiencies those advances offer\u2014are making this one of the hottest fields in computing. Major figures in networking and communications research gather in Hong Kong from August 12 to 16 for SIGCOMM…","locale":{"slug":"en_us","name":"English","native":"","english":"English"},"_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/posts\/287960"}],"collection":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/users\/39507"}],"replies":[{"embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/comments?post=287960"}],"version-history":[{"count":4,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/posts\/287960\/revisions"}],"predecessor-version":[{"id":288335,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/posts\/287960\/revisions\/288335"}],"wp:attachment":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media?parent=287960"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/categories?post=287960"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/tags?post=287960"},{"taxonomy":"msr-research-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/research-area?post=287960"},{"taxonomy":"msr-region","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-region?post=287960"},{"taxonomy":"msr-event-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event-type?post=287960"},{"taxonomy":"msr-locale","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-locale?post=287960"},{"taxonomy":"msr-post-option","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-post-option?post=287960"},{"taxonomy":"msr-impact-theme","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-impact-theme?post=287960"},{"taxonomy":"msr-promo-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-promo-type?post=287960"},{"taxonomy":"msr-podcast-series","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-podcast-series?post=287960"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"data-center](\"https:\/\/www.microsoft.com\/en-us\/research\/wp-content\/uploads\/2016\/09\/data-center-networking.png\")