|By Marten Terpstra||
|October 17, 2013 04:00 PM EDT||
The past few years have seen a dramatic improvement in the latency in network switches. Single ASIC based switches can all pretty much switch packets in less than a microsecond. Current 10GE switching silicon provides anywhere from 300 to 800 nanoseconds, specialized silicon shaves that to less than 200 nanoseconds when limiting the amount of searching that needs to be done by reducing the size of lookup tables. Even other solutions play some smart tricks by providing forwarding hints for intermediate switches make those lookups take less than 50 nanoseconds.
Modular switches inherently have a higher latency. Line cards on modular switches typically have multiple ASICs, those ASICs are connected through a single or multi stage fabric. Each step takes time, resulting in latencies varying from around a microsecond when a packet stays on the same ASIC, to possibly 5-15 microseconds when a packet needs to travel through the fabric and back.
The speediest of ASICs achieve these low numbers by employing cut through switching. Cut through switching allows the ASIC to start transmitting a packet when enough of the header has been received to make a forwarding decision. The ASIC does not wait for the entire packet to be received (the more traditional store-and-forward mechanism), within the first few 100 bytes the forwarding decision has been made, and that same header (modified or not) is being transmitted out the destination port. It's somewhat odd to think that through, but the first bits of a packet may be received by the destination system before the last bits have left the first switch in the network.
Cut through switching comes with quite a few "buts". Most switches can only deploy cut through switching when the source and destination port are the same speed. 10GE in and 40GE out or vice versa is rarely supported and the ASIC will automatically switch to store-and-forward for those packets. For good reason. If a packet comes at you at 40GE rates, you simply cannot transmit it out a 10GE interface, that interface is not fast enough. In the reverse direction speed is not the issue, but if you were to employ cut through switching, for the duration of that packet your 40GE interface effectively runs at 10GE with lots of pauses in between pieces of a packet (figuratively speaking).
In addition, when the destination port has another packet being transmitted or in the queue, a new packet cannot be sent cut through. When another packet is ahead of you, you need to wait. And you may need to wait for quite a while. We often forget that it takes 1.2 microseconds to transmit a 1500 byte packet on a 10GE interface, more than 7 microseconds for a jumbo packet. When the destination port is being paused due to Data Center Bridging Priority Flow Control (PFC), the packet will be queued for store and forward. And make sure you add an extra 3 microseconds for 10GBASE-TX.
Datacenters are on a path to fewer layers of switching. Spine and leaf networks are being pitched as the best performing, low cost solution for dense networks. If you carefully examine the specs and pitches of some of the newer spine switches, you will notice that all of them make a case for deep buffers. Deep buffers assume that this switch needs to manage congestion by buffering packets, why else would you design expensive and power hungry buffer memory into those switches. Buffering and low latency don't go well together. If your spine and leaf network has nothing much to do, you may well see latency numbers of only a few microseconds or better. If the spine layer needs to buffer your packet, this number can jump up quickly to 10s of microseconds. And those large buffers seem to suggest it will.
There certainly are applications that are very sensitive to latency. Financial institution low latency trading networks are the example always used, and there are High Performance Computing environments with database, RDMI or similar applications that benefit from really low latency. Engineering the traffic in such a way that none of the low latency disruptive events described above happen is hard. Really hard. Extremely hard if there is a lot of traffic. Or a lot of endpoints. Networks that are specifically designed to aggregate and distribute (spine and leaf) will be more prone to these latency increasing scenarios. Creating a network with the ability to create isolated direct paths between switches that serve low latency applications is much more likely to avoid these. And even if the absolute latency is not the lowest, consistent latency with little jitter will certainly help the performance of adaptive mechanisms like TCP.
Web Real-Time Communication APIs have quickly revolutionized what browsers are capable of. In addition to video and audio streams, we can now bi-directionally send arbitrary data over WebRTC's PeerConnection Data Channels. With the advent of Progressive Web Apps and new hardware APIs such as WebBluetooh and WebUSB, we can finally enable users to stitch together the Internet of Things directly from their browsers while communicating privately and securely in a decentralized way.
Mar. 25, 2017 03:00 AM EDT Reads: 5,639
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor - all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
Mar. 25, 2017 01:45 AM EDT Reads: 1,411
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
Mar. 25, 2017 12:15 AM EDT Reads: 1,541
What sort of WebRTC based applications can we expect to see over the next year and beyond? One way to predict development trends is to see what sorts of applications startups are building. In his session at @ThingsExpo, Arin Sime, founder of WebRTC.ventures, will discuss the current and likely future trends in WebRTC application development based on real requests for custom applications from real customers, as well as other public sources of information,
Mar. 25, 2017 12:00 AM EDT Reads: 445
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
Mar. 24, 2017 11:45 PM EDT Reads: 623
TechTarget storage websites are the best online information resource for news, tips and expert advice for the storage, backup and disaster recovery markets. By creating abundant, high-quality editorial content across more than 140 highly targeted technology-specific websites, TechTarget attracts and nurtures communities of technology buyers researching their companies' information technology needs. By understanding these buyers' content consumption behaviors, TechTarget creates the purchase inte...
Mar. 24, 2017 10:15 PM EDT Reads: 4,145
With the introduction of IoT and Smart Living in every aspect of our lives, one question has become relevant: What are the security implications? To answer this, first we have to look and explore the security models of the technologies that IoT is founded upon. In his session at @ThingsExpo, Nevi Kaja, a Research Engineer at Ford Motor Company, will discuss some of the security challenges of the IoT infrastructure and relate how these aspects impact Smart Living. The material will be delivered i...
Mar. 24, 2017 10:00 PM EDT Reads: 1,875
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
Mar. 24, 2017 08:15 PM EDT Reads: 299
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
Mar. 24, 2017 06:30 PM EDT Reads: 4,123
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
Mar. 24, 2017 06:30 PM EDT Reads: 2,618
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
Mar. 24, 2017 05:15 PM EDT Reads: 1,307
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
Mar. 24, 2017 04:45 PM EDT Reads: 1,776
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
Mar. 24, 2017 01:15 PM EDT Reads: 3,851
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
Mar. 24, 2017 12:45 PM EDT Reads: 1,867
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
Mar. 24, 2017 12:15 PM EDT Reads: 970
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
Mar. 24, 2017 12:00 PM EDT Reads: 1,896
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
Mar. 24, 2017 12:00 PM EDT Reads: 1,650
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
Mar. 24, 2017 10:45 AM EDT Reads: 1,436
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
Mar. 24, 2017 09:45 AM EDT Reads: 2,744
Now that the world has connected “things,” we need to build these devices as truly intelligent in order to create instantaneous and precise results. This means you have to do as much of the processing at the point of entry as you can: at the edge. The killer use cases for IoT are becoming manifest through AI engines on edge devices. An autonomous car has this dual edge/cloud analytics model, producing precise, real-time results. In his session at @ThingsExpo, John Crupi, Vice President and Eng...
Mar. 24, 2017 08:45 AM EDT Reads: 3,690