Fiber Optics Solutions

petak, 26.06.2015.

Making the Case for 10 Gigabit Ethernet

Several factors make 10GbE implementations a compelling option, including interoperability, cost efficiency, low power consumption, communication quality, and hardware availability. Each of these factors merits careful consideration.

Interoperability Leveraging Existing Technology

During infrastructure upgrades, 10GbE and the TCP/IP protocol are designed to interoperate seamlessly with GbE links, enabling a relatively easy and nondisruptive transition to 10GbE. Two different types of 10GbE connectors are expected to facilitate these links, including 10GBase-T copper and the 10GbE small form-factor pluggable+ (SFP+) interconnect. SFP+ supports different physical port types such as 10GBASE Twinax copper and various types of fiber connections.

By helping ensure that the 10GbE components can cooperatively communicate with GbE devices, switch vendors can deliver interoperability between GbE and 10GbE. Data transitioning from 10GbE to GbE links potentially requires additional buffering on the 10GbE switch to temporarily store the data while it is being transmitted to a low-speed device. In addition, support can be provided for the expected Ethernet standard pause frames (IEEE 802.3x) and priority flow control standards that are part of the enhanced Ethernet standards.

Cost Efficiency Resulting from Fewer Connections

Over time, as 10GbE becomes commonplace, one 10GbE port is expected to be more cost-efficient than multiple GbE ports and Fibre Channel ports. Current GbE storage normally requires multiple ports to provide acceptable storage bandwidth between hosts and arrays. Based on industry best practices for redundancy, a minimum of two connections are used to provide a failover path between host and storage. Additional bandwidth may be required by the application—for example, the performance of sequential data applications such as data warehouses is typically gated by bandwidth. Another best practice is to isolate storage traffic on the SAN from client/server traffic on the LAN, which requires a separate LAN port. Dedicated management ports are often required as well. Just two 10GbE connections (for minimal redundancy) in conjunction with enhanced Ethernet standards such as DCB can handle these requirements while still upholding the best practices just described.

Figure 1 Transitioning to 10GbE connections
Figure 1. Transitioning to 10GbE with iSCSI, Fibre Channel, and FCoE connections

Low Power Consumption with SFP+ optics

Since the 10GBase-T standard was adopted in 2007 for twisted-pair copper cabling, efforts have been underway to help reduce 10GBase-T power consumption—with a goal of reaching power levels per port that are equivalent to the current 1GBase-T standard. First-generation 10GBase-T adapters have higher wattage demands than their short-reach optical counterparts. Currently, prototype second-generation 10GBase-T implementations are designed to bring wattage demand per port down to reasonable levels.

10GbE SFP+, which today is an early implementation choice for network and storage vendors such as Dell, Cisco, HP, etc. that has very low wattage requirements per port, and SFP+ direct attach copper cable can provide a power-efficient, cost-effective 10 m cabling reach between rack-mounted servers and a top-of-rack switch.

In SFP+ direct attach connections, the module is built into the cables (SFP+ cable). This effort, along with the reduction in the number of separate connections required to manage multiple networks, should help significantly reduce the power requirements of the network.

Communication Quality with Compliant Standards

The Data Center Bridging (DCB) standard is expected to encompass several IEEE 802.1 standards to help ensure communication quality for 10GbE and iSCSI deployments. Priority flow control (802.1Qbb), a link-level flow-control mechanism, is designed to ensure zero loss under congestion in DCB networks. Another standard, 802.1Qau, is intended to provide end-to-end congestion management.

Hardware Availability to Mix GbE and 10GbE

Hardware is available today for mixing GbE and 10GbE. For example, the Dell PowerConnect M8024 blade I/O switch modules can configure ports to run at GbE or 10GbE speeds and provide several options for physical connection types; SFP+ optics use in GbE and 10GbE Ethernet links, such as the Finisar FTLX8571D3BCV 1G/10G Dual-Rate SFP+ optical transceiver over multimode fiber and FTLX1471D3BCV 1G/10G Dual-Rate SFP+ optical transceiver link length up to 10km over singlemode fiber. When used in conjunction with an external 10GbE switch, such as the planned PowerConnect 8024F SFP+ switch, and legacy GbE switches, such as the PowerConnect 6200 series, this hardware is expected to offer several options for configuring iSCSI storage solutions that utilize mixed Ethernet speeds.

Refers to Dell Mixing Gigabit Ethernet and 10 Gigabit Ethernet in a Dedicated SAN Infrastructure

Oznake: Gigabit Ethernet, SFP+ cable, FTLX8571D3BCV, FTLX1471D3BCV

26.06.2015. u 09:13 • 0 Komentara • Print • #

utorak, 28.04.2015.

Knowledge of 1G 10G Dual-Rate Optical Transceiver

As data centers and enterprises strive to future proof their infrastructures while maximizing their current networks, the flexibility of true dual-rate compliant interfaces eases the transition to higher Gigabit Ethernet systems. This is why the dual-rate optical transceiver has emerged (e.g. Finisar FTLX8571D3BCV and FTLX1471D3BCV). And today, I'd like to talk something about the dual-rate optical transceiver, particularly the 1G/10G dual-rate SFP+.

The following figure shows Finisar FTLX8571D3BCV compatible 1G/10G Dual-Rate SFP+ optical transceiver

As its name suggests, dual-rate optical transceiver is a kind of optical transceiver which can support two different data rates. With the dual-rate optical transceiver, users can achieve the full forward and backward compatibility of their systems with a low cost. The common dual-rate optical transceivers in the today's market is the 1G/10G dual-rate SFP+ transceiver. They are compatible with either 10 Gigabit Ethernet or 1 Gigabit Ethernet fiber interface. There are many different vendors to supply the 1G/10G dual-rate SFP+, but the standards and protocols which they complied with are the same. In general, the 1G/10G dual-rate SFP+ are designed for use in 1 Gigabit and 10 Gigabit Ethernet links over single-mode or multi-mode fiber. They are compliant with SFF-8431, IEEE 802.3-2005 10GBASE-SR/SW, 10GBASE-LR and 1000BASE-SX, 1000BASE-LX. In addition, similarjavascript:%20void(0); to most modern optical transceivers, digital diagnostics monitoring (DDM) or digital optical monitoring (DOM) functions are also available in the dual-rate SFP+, so that users can monitor many parameters of the transceiver module in real-time. Actually, with the development of technology and the increasing demands on higher Gigabit Ethernet, there are other dual-rate optical transceivers with different package styles or even at different data rates except the 1G/10G dual-rate SFP+, eg. Multi-rate XFP.

In my opinions, the emergence of dual-rate optical transceiver is mostly because of the cost consideration. From 1G to 10G, 10G to 40G, 40G to 100G, and even higher data rate, it means that the development of Gigabit Ethernet is very fast. In other words, the cost of updating the equipment keeps adding up over time. Dual-rate optical transceiver is a cost-effective solution to solve this question. For example, a 1G/10G dual-rate SFP+ can be used in both 1 Gigabit Ethernet and 10 Gigabit Ethernet links which eases the transition from 1Gb/s to 10Gb/s systems. Users can configure to operate the dual-rate optical transceivers at 1GbE or 10GbE in a switch with 10G SFP+ ports and 1G/10GSFP+ ports, but not native 1G SFP ports. And do not have to spend extra cost in buying optical transceivers only support 1G or 10G Ethernet. Of course, if you only need one type of Gigabit Ethernet, you do not need to use the dual-rate optical transceiver. So, at this time, the more cost-effective choice is to buy a corresponding single-rate optical transceiver. Nowadays, 10G Ethernet is the most commonly used type of Ethernet as the 40G and 100G are still developing. Thus, the market of 1G/10G dual-rate SFP+ is not so popular as its first emergence. But it is still applied in 1000BASE-SX 1G Ethernet, 1000BASE-LX 1G Ethernet, 10GBASE-SR/SW 10G Ethernet and 10GBASE-LR 10G Ethernet as a cost-effective solution for 1G/10G Ethernet.

From this paper, you may have an understanding of the dual-rate optical transceiver. No matter you are very familiar with the dual-rate optical transceiver or have no idea of it, I really hope that this paper is useful for you. Of course due to the limited knowledge of me, there may be some inevitable errors and omissions existing in this paper. If it is not appropriate, your critical comments are highly appreciated.

More knowledge of optical transceiver: Knowledge of Dual-rate Optical Transceiver

Oznake: FTLX8571D3BCV, Dual-rate SFP+, 1000BASE-SX, optical transceiver

28.04.2015. u 11:28 • 0 Komentara • Print • #

četvrtak, 15.01.2015.

When It's Best to Use GBIC and When to Use SFP?

Recently many users ask when they choosing a card for their switch/router, they should choose either cards that take SFP or cards that take GBIC. It seems to be a headache for them because they are not clearly know the differences of them. Thus, today, we are mainly going to discuss that when it's best to use GBIC and when to use SFP.

GBIC (gigabit interface converter)

GBIC is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. GBIC is a standard for transceivers, commonly used with Gigabit Ethernet and fiber channel. GBIC module is hot pluggable, this feature allows a suitably designed enclosure to be changed from one type of external interface to another simply by plugging in a GBIC having the alternative external interface. Generally, GBIC is with the SC connector. The GBIC standard is non-proprietary and is defined by the Small Form Factor committee in document number 8053i. The first publication of the proposal was in November 1995. A few corrections and additions were made through September 2000.

GBIC

SFP (small form-factor pluggable)

SFP is a specification for a new generation of optical modular transceivers. The form factor and electrical interface are specified by a multi-source agreement (MSA). SFP is also known as a Mini GBIC as its function is somewhat similar to the GBIC transceiver while SFP is smaller than it. SFP transceivers are designed to support SONET, gigabit Ethernet, Fibre Channel, and other communications standards. Due to its smaller size, SFP is now more and more widely used for both telecommunication and data communications applications.

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GBIC & SFP Interface Types

For every type of GBIC and SFP transceivers, it works with different wavelengths at a designated location or distance. For examples, SX SFP uses 850nm for a maximum of 550 meters, LX SFP uses 1310nm for a maximum 10km, ZX SFP could reach 80km or copper SFP uses a RJ45 interface. We can easily distinguish via the information in their names or models, ie. 1000BASE-T SFP, 1000BASE-SX SFP, 1000BASE-LX/LH SFP, 1000BASE-ZX SFP, 1000BASE-CWDM SFP, or 1000BASE-DWDM SFP. In addition, the DOM function for an SFP is discretionary. It supports the users to locate the real-time working status of SFP. The famous brand of GBICs or SFPs are Cisco, Finisar, HP, Juniper, Extreme Network and so on. There is a little difference in the features of each brand's GBICs and SFPs and they support their corresponding brand's switches/routers.

When it's best to use GBIC and When to use SFP?

According to the above definitions of GBIC and SFP, you may have a further understanding on both of them. There is only one difference of them. SFP is smaller than GBIC. Because the smaller size of SFP (almost half the volume of GBIC), we can configure double number of ports on the same panel which increases the utilization rates of switches/routers. Other basic functions of SFP is almost the same with the GBIC and they are equal in performance. Though there are some users still using the GBIC as their old divice which can not be updated to support SFP, GBIC will gradually be obsoleted and replaced by SFP. So the answer to the question "When it's best to use GBIC and When to use SFP?" is obvious. SFP is your choice. Of course, except GBIC and SFP, there are SFP+, XFP, QSFP/QSFP+ etc. new generation of transceivers which can meet all kinds of your requirements. These new types of transceivers will be discussed in other aticle and not state here one by one. If you are interested in them, please focus continuously on my blog. Or if you need these products, Fiberstore will be a good place for you.

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