To process data from various internal and external sources into meaningful information is not a simple task. The increase in the amount of data (meaningful or meaningless, structured or unstructured), as well as the speed at which this has to be processed, has steadily increased. The Universal Arista Cloud Network Architecture provides a number of specific advantages, making it ideal for data center infrastructure to process this data.
- North-South vs East-West topology
By virtualizing servers and applications, a new source of information is on it’s way which requires a different network topology. The former North-South (User to Application) has been changed in an East-West (Application to Application) information. As a result, the Access Distribution Core (3-Tier) topology is no longer the best fit. Direct Access Core (2-Tier) topology provides a shortcut from application to application and is therefore inherently faster. These 2-Tier topology is also called Leaf-Spine topology.
- IP (Layer 3) switching vs Ethernet (Layer 2) switching
In the past couple of years more and more DC switching architectures have been built using Layer 2 Ethernet. Flexibility in growth and speed are key factors. The easily customizable Ethernet network layer has caused the changes in server and storage layer to be tracked (using VMware) and have led to Ethernet fabric deployments. For the layer 3 routing, additional complex external routers are needed. Equal Cost Multi-Path Routing (ECMP) and Multi-Chassis Link Aggregation (MLAG) protocols have the flexibility of Ethernet Fabrics but by using this now for Layer 3, this invalidates the need for complex routers.
- Leaf-Spine vs. Arista's SPLINE ™ Topology
Based on the above, Arista developed SPLINE ™ network design. This topology is further reduced to a single layer (Top of Rack switches are directly connected to each other) so that applications themselves communicate directly with each other (one hop less). Because the SPLINE ™ design is not applicable in all cases Arista has retained the freedom to combine combinations of 2-Tier (Leaf-Spine) with single tier (SPLINE ™). Also, VXLAN Overlay (Layer 2 over Layer 3) to configure designs, so that applications that are not in an L3 Switched (BGP) environment can work, yet retain the advantages of L3 network switches.
- Modular Software and Single Software Image
Arista has built its switch operating system (EOS) and modular software. By using a central sysDB which tracks all the states of the various software processes and only exchanges processes through this sysDB information, there is a decoupling between the different processes. The advantage is that no proces can consume so many resources a switch becomes overloaded and fails.
Additionally, you can perform SW bug fixes on the fly, execute extensions (by copying the sysDB and putting it on a new switch, the switch is immediately actively connected to the network) and even an upgrade can be operated within milliseconds so an outside service window is created.
Arista EOS is a single image that is active on all Arista switches. The licensing model is up to 3 levels (Switching, Routing and VXLAN: Layer2 on layer 3) is limited and depending on the data center topology.
- iSCSI& NAS vs FiberChannel
Viewed from the world of storage networking, comparable virtualization trends can be distinguished. Software Defined Storage (SDS) and iSCSI over Ethernet make storage virtualization possible on the well-known and cheaper Ethernet networks without the need for specific SAN switches.
Hybrid (or migration) designs combine both worlds, with high speed (10, 40 100GigE) Ethernet and (4, 8 and FC16) Fiber Channel are combined in the WDM Data Center Interconnect (DCI) infrastructure.
- High Speed ??Ethernet Interfaces: 10, 25, 40, 50 and 100 Gb/s
(Multi-core) servers with increasingly powerful processors are expanding the throughput. The connection to the network passes the 10Gb/s. For this, there have recently been two new speeds certified with 25 (twisted pair and optical) and 50Gb/s (only optical).
- Deep Buffers
Particularly for Big Data or other intensive data center applications, Arista has specific data center switches (SW same image as the general purpose switches EOS) and developed additional hardware features. The most important of these are: 1) a cell-based (as opposed to the flow-based) backplane that prevents it from becoming overloaded and one of the backplane fabrics (also called hashing) thereby limits the performance. 2) Extra-large buffer memory allowing for asynchronous traffic (high incoming traffic on incoming ports that have to go out through an output port) no buffer overflows occur, and it reduces the overall throughput.
- Low Latency
By making use of commercial of the shelf ASICs (mergin Silicon) and Arista's own software developments (rather than using the SDKs), data center switches develop a very small delay (low latency), and the majority (> 70 % market share) of the high frequency traders, are used. Because of mass production (more manufacturers use these) the mergin Silicons have the advantage that the price remains acceptable and that the newly available ASICs can be deployed rapidly.
- Management and Cloud Vision ™
Arista's EOS and sysDB functionality makes it possible to include new switches in the network and (have) to load a copy of the sysDB of another switch (Zero Touch Provisioning). This switch is thus incorporated directly into the network.
Additionally Arista has a developed a netDB function next to sysDB. This netDB in each switch allows, in combination with the Cloud Vision central software, for which there is a database in which every moment is included the status of the sysDB. With this you can see in real time how the network reacts (and thus eg. Detect microburst), but also look back just in time what was the status of the network.
Cloud Vision also provides the tools (APIs) to the partner ecosystem Arista for management interaction with SDN controllers, virtualization SW, FW vendors, etc.
- Rackspace & Energy
The new leaf-spine and SPLINE ™ topology reduces the number of required (distribution / aggregation and core) switches and routers. Add this to the new Ethernet port speeds of 25 and 50 Gb/s, allowing a higher capacity per port can be offered. Just these two factors dramatically reduce rack space and power consumption (watt per Gb/s).