What Ethernet Standards can be used with SFP+ ?

by www.fiber-mart.com

The enhanced small form-factor pluggable (SFP+) is an enhanced version of the SFP that supports data rates up to 16 Gbit/s.

 

The SFP+ specification was first published on May 9, 2006, and version 4.1 published on July 6, 2009. SFP+ supports 8 Gbit/s Fibre Channel, 10 Gigabit Ethernet and Optical Transport Network standard OTU2. It is a popular industry format supported by many network component vendors.

 

SFP+ connectivity are the most flexible and scalable Ethernet adapters for today’s demanding data center environments. The escalating deployments of servers with multi-core processors and demanding applications such as high performance computing (HPC), database clusters, and video-on-demand are the types of applications driving the need for 10-gigabit connections.

 

10 Gbit/s SFP+ modules are exactly the same dimensions as regular SFPs, allowing the equipment manufacturer to re-use existing physical designs for 24 and 48-port switches and modular line cards.

 

Although the SFP+ standard does not include mention of 16G Fibre Channel it can be used at this speed. Besides the data rate, the big difference between 8G Fibre Channel and 16G Fibre Channel is the encoding method. 64b/66b encoding used for 16G is a more efficient encoding mechanism than 8b/10b used for 8G, and allows for the data rate to double without doubling the line rate. The result is the 14.025 Gbit/s line rate for 16G Fibre Channel.

 

Like previous versions of Ethernet, 10GbE medium can be either copper or optical fiber cabling.  However, because of its bandwidth requirements, higher-grade copper cables are required: category 6a or Class F/Category 7 cables for lengths up to 100 meters. The 10 Gigabit Ethernet standard encompasses a number of different physical layer (PHY) standards.

 

SFP+ modules do only optical to electrical conversion, no clock and data recovery, putting a higher burden on the host’s channel equalization. SFP+ modules share a common physical form factor with legacy SFP modules,

 

Select the appropriate transceiver to provide the required reach. Depending on the product, you can obtain SFP+ transceivers for cable distances of up to 15 meters (m), 400 m, 10 kilometers (km), 40 km, and 70 km. Alternatively, you can use a direct attach cable.

 

PHY TYPE

 

REACH

 

10GBASE-SR

 

Up to 300m link length with 2000 MHz*km MMF (OM3). Optical interoperability with 10GBASE-SRL

 

10GBASE-SRL

 

Up to 100m link length with 2000 MHz*km MMF (OM3). Optical interoperability with 10GBASE-SR

 

10GBASE-LRM

 

Up to 220m link length with 50 μm or 62.5 μm MMF links

 

10GBASE-LR

 

Up to 10km link length on standard single-mode fiber (SMF, G.652)

 

10GBASE-CR

 

Pre-terminated twin-ax copper cables with link lengths of 1m, 2m, 3m and 5m (SFP+ to SFP+ or QSFP to 4 x SFP+)

 

Bi-Directional Single Strand

 

Unlike previous Ethernet standards, 10 Gigabit Ethernet defines only full duplex point-to-point links which are generally connected by network switches; shared-medium CSMA/CD operation has not been carried over from the previous generations Ethernet standards. Half duplex operation and repeater hubs do not exist in 10GbE.

 

Multiple vendors have introduced single strand, bi-directional 10 Gbit/s optics capable of a single-mode fiber connection functionally equivalent to 10GBASE-LR or -ER, but using a single strand of fiber optic cable. Analogous to 1000BASE-BX10, this is accomplished using a passive prism inside each optical transceiver and a matched pair of transceivers, using a pair of wavelengths such as 1310 nm / 1490 nm or 1490 nm / 1550 nm. Modules are available in varying transmit powers and reach distances ranging from 10 to 80 km.