What is InfiniBand and what is it used for?

What is InfiniBand and what is it used for?

 

INTRODUCTION :

 

InfiniBAnd (IB) is actually a trademark term used since 1999, it was formerly called System I/O. InfiniBand was coined surprisingly when two dueling designs in the market merged, this happened after realizing that it is the right approach to prevent future limitations in the industry, because the existing designs would no longer meet the needs of future servers.

 

The two competing designs were:  Future I/O – developed by IBM, Compaq and Hewlett-Packard, and Next Generation I/O – developed by Microsoft, Intel and Sun Microsystems.  With confidence that both the industry and the end-users will benefit from the merging, they formed the InfiniBand Trade Association or IBTA which has over 220 members, currently.

 

Future I/O and Next Generation I/O are Input/output architectures were expected to replace the traditional PCI or Peripheral Component Interconnect system. Why is there a need to replace the PCI bus?  Mainly because, the PCI bus became the bottleneck limiting the performance of high-speed data servers for the reason that, it is restricted to about 500 Mbps of shared data only. PCI dominated the industry since early 90’s with one major upgrade during the period: from 32 bit/ 33 MHz to 64bit/66Mhz. The PCI-X which made the technology one step advanced to 133 MHz was projected to pro-long PCI architecture usage in the industry. However, Internet became so popular globally, continually increasing in demand to almost no downtime at all. The need to constantly accessible, dependable high-performance with fail-safe system which are services provided by the web, data storage features of internet, applications, database servers and enterprise computing software systems, etc. has changed the game plan of the market players.  Moreover, many opt to move storage out of the server to isolated storage networks and distribute data across fault tolerant storage systems is now a trend in the industry.  Such demands require more bandwidth and that bus system have reached the level that PCI interconnect architecture can no longer cater.

 

So IBTA, came up with the so-called, InfiniBand. What is Infiniband?

 

InfiniBand is a switch-based point-to-point serial I/O interconnect architecture developed for today’s system with the ability to scale next generation system requirements.  It is operating based on a four-wire 2.5 Gb/s or 10 GB/s base speed per individual port link in each direction.  It is a low pin count serial architecture connecting devices on the PCB as a component-to-component interconnect and enabling “Bandwidth Out of the Box”, chassis-to-chassis interconnect, traversing distances up to 17m over common twisted pair copper wires.  Compared to ordinary fiber cable, it can go over distances of a number of kilometers or more. Its architecture described a layered hardware protocol; Physical, Link, Network, Transport Layers and a software layer to manage initialization and communication between devices.

 

Different USES of  InfiniBAnd

 

RAS(Reliability, Availability, Serviceability) provider

InfiniBand provides RAS (Reliability, Availability, Serviceability) capabilities designed into the InfiniBand. RAS refers to a fabric that works both in-the-box and allows Bandwidth Out of the Box.  Because of this RAS feature, it is projected that InfiniBand architecture will be able to serve as the common I/O infrastructure for the next generation of computer server and storage systems at the heart of the Internet. Hence, this will fundamentally alter the systems and interconnects the Internet infrastructure.

 

Supports Application Service Providers or ASP

The Internet, from simple online data search engine to supporting numerous applications, creating international market for media streaming, business to business solutions, E- commerce and interactive portal sites.  The demand for reliability of each application created tremendous pressure to service providers. Application Service Providers or ASP entered in, a group offering quality services with the capacity to intensely gauge in a short period of time to accommodate drastic growth of internet despite possible congestion using the cluster to support above requirements.  A cluster is group of servers connected by load balancing switches working in a parallel to serve a particular application.  InfiniBand makes application cluster connections simplified by interconnecting or fusing network with a feature-rich managed architecture. It delivers native cluster connectivity, devices can be attached and multiple paths can be used with the addition of switches to the fabric. 

 

QoS or Quality of Service

 InfiniBand at the same can deliver and process transactions of high importance between devices prioritizing over the less significant items through built-in QoS or Quality of Service mechanisms.

 

Scalability for IPC or Inter-Processor Communications

The switched nature of InfiniBAnd offers connection reliability for IPC or Inter-Processor Communications systems by allowing multiple paths between systems. Scalability is sustained with fully convertible connections managed by a single unit which is the subnet manager. With multi-cast support feature, single transactions can be made to multiple destinations. Consequently, InfiniBand served as a backbone in the capabilities for IPC clusters by allowing multiple servers work together on a single application without the need of secondary I/O interconnect because of the higher bandwidth connections (4X/12X) it can provide.

 

Storage Area Networks (SAN) simplified

These are groups of complex storage systems linked together to managed switches to allow vast volumes of data to be stored from multiple servers. They provide dependable connections to large database of information that the Internet Data Center requires. Basically, SAN are built using Fibre Channel switches, servers and hubs attached through Fibre Channel Host Bus Adapters (HBA). But the emergence of InfiniBAnd results from removal of Fiber Channel Network and lets servers connect directly to a storage area network eliminating the pricy HBA. With features like the Remote DMA(RDMA) support, simultaneous peer-to-peer communication and end-to-end flow control, InfiniBand through its fabric topology overcomes the deficiencies of Fibre Channel; such as, restriction of data that individual servers can access which arises to “partitioning mechanism”, or sometimes termed as zoning or fencing without the aid of a costly and complex HBA.