Is the GLC-SX-MMD Transceiver Right for Your Network?

Growing businesses typically requires higher-bandwidth networks. It is an unavoidable trend. The old-decade technology like Base-T Ethernet works just fine for small office, but it isn’t sufficient to handle heavier network. Thus if you are in the situation to consider purchasing a large property, or opening up a second office, it is time for you to think about upgrading to Gigabit Ethernet, which moves at ten times the speed of traditional Ethernet. However, there are a number of issues involved in a major network infrastructure transition.

When planning a move to gigabit Ethernet, one of the most urgent concerns is how much new hardware designers have to purchase. The basic components like fiber optic cable and optical transceiver modules are indispensable. These inexpensive Small Form-factor Pluggable (SFP) slots allow transceivers like the GLC-SX-MMD to be plugged in and provide instant gigabit Ethernet connectivity. The Cisco standard SFP transceiver allows data rate of 1000Mbps with DOM support. The max transmission distance is 550m over OM2 multimode fiber. So here comes the question, is the GLC-SX-MMD transceiver (see in Figure 1) right for your network?

Fiber Optic Gigabit Ethernet vs Twisted Copper

As noted before, GLC-SX-MMD transceiver operates over multimode fiber at rate of up to 1000Mbps. Using copper-wire cabling or fiber optic cabling like above is the unsolved dilemma when contemplating a network. It is the common sense that fiber optic cabling is more expensive than twisted copper cabling, but fiber optic provides several advantages over copper with the same gigabit speeds.

First, fiber optic supports longer link distance than twisted copper. For instance, copper can only run for around 100 meters, whereas fiber can go between 200 and 500 feet, or more, without signal loss. Fiber has given off no radio interference, allowing it to coexist more easily in an office with a lot of wireless devices. Because of the lack of interference, fiber is also harder to hack into than copper. What’s more, for future proofing, moving away from copper is probably a good idea, as the fiber optics are growing steadily in popularity among businesses which have taken over large twisted-copper office buildings, created expansive complexes, or need to collaborate with remote offices in real time. Figure 2 shows a standard GLC-SX-MMD transceiver links fiber optic Ethernet with Cisco Switch.

Using a GLC-SX-MMD for Fiber Optic Gigabit Ethernet

GLC-SX-MMD, as a representative of the standard Cisco SFP, is widely utilized for short-reach Gigabit Ethernet. As we know, the biggest advantage of Cisco's SFP system is that it's entirely hot-swappable. It doesn't matter what the device is, from servers to your switch to simple Ethernet cards: If it has an SFP port on it, it can support a multitude of transceivers for different functions, through one standardized interface. In fact, that standardization means that third parties can produce transceivers which are as good as official Cisco units.

Cisco even maintains a Compatibility Matrix, to help you pick the right transceiver for the job. So, if you decide that fiber optic gigabit Ethernet is what you need for your future business communications, the GLC-SX-MMD transceiver is truly simple to install and use. Simply plug it into your switch or other device, plug in the new network cable, and it should recognize the network in a few moments.

Conclusion

For those who still use copper network or lower-bandwidth application, it’s time for them to think about upgrading their infrastructure. And there are several different gigabit Ethernet standards out there, you can see which best fits your vision for the future of your business. Just keep in mind that you will need an optical transceiver like the GLC-SX-MMD to connect your existing devices to the new network. Fiberstore manufactures high-quality fiber optical transceivers, like 100BASE SFP, 1000BASE SFP, BiDi SFP, CWDM/DWDM SFP Transceiver Module and SONET/SDH SFP, besides Compatible GLC-SX-MMD transceiver with lower price. GLC-SX-MM-RGD and GLC-SX-MM are also offered. If you have any requirement of our products, please contact us directly.

The Evolution Path of BASE-T

With the requirements laid on data center increasing rapidly, the ability to flexibly adapt to future demands is tremendously crucial for data center managers. Often this can be achieved by deploying higher bandwidth solutions in a part of the data center, provided that these systems are backwards compatible with existing infrastructure or it may be a cost-consuming method. BASE-T technology featured by its low cost, availability and flexibility is largely favored by data center designers. This article illustrates the migration of BASE-T technology so that people can future proof their data center tomorrow.

Why BASE-T Is so Popular?
To be short, three main advantages will be concluded in the following part.
1. Least cost access layer alternative when compared to other interconnect technologies

• Optical (e.g. SR, LR)
• Direct-Attached

2.Structured topology

• Common physical interface (RJ45)
• Flexibility and longevity
• Optimized for small to medium-sized data centers (< 20K square feet)

3. Supports auto-negotiation and Power-Over-Ethernet

• Simple plug and play installation
• Ubiquitous RJ45 interface simplifies 10GBASE-T to 40GBASE-T upgrade path

1000BASE-T—Gigabit Ethernet Over 4-pair Cat 5 Cabling
1000BASE-T (ratified in 1999) is a Gigabit Ethernet standard over copper wiring at the speed of 1000 Mbps. Each 1000BASE-T network segment can support a maximum length of 100 meters, and uses Category 5 cable or better (including Cat 5e and Cat 6). 1000BASE-T also uses a symbol rate of 125 Mbaud and all four pairs for the link and a more sophisticated five-level coding scheme. The 1000BASE-T SFP operates on standard Category 5 unshielded twisted-pair copper cabling of link lengths up to 100 m.

Realizing 10BASE-T
Upgraded from 1000BASE-T, 10GBASE-T (certificated in 2006) offers the most flexibility, the lowest cost media, and is backward-compatible with existing 1 GbE networks. 10GBASE-T connected with Cat 6 and Cat 6A (or above) cabling supports a length up to 100 meters that gives IT managers a far greater level of flexibility in connecting devices in the data center. 10GBASE-T and Category 6A cabling costs less than using either optical fiber or SFP+ direct attach copper (DAC) options that have been widely deployed to date center for 10 Gb/s. For example, EX-SFP-10GE-DAC-1M can only support a link length of 1m that largely limits its application. Figure 1 presents a comparison between 1000GBASE-T and 10GBASE-T.

Road to 40GBASE-T in Data Center Networks
If there is a 10GBASE-T for switch-to-server and switch-to-switch connectivity, there will be a 40GBASE-T over twisted pair cabling for the 40G data center deployment according to the IEEE. Twisted pair cabling with the RJ-45 connector has always been the first choice for IT professionals, based on its low cost and ease of use. Unlike fiber or twinax solutions, twisted pair cabling can automatically switch to different data rates, such as from 100MbE to 10GbE. Therefore migration to 40GBASE-T does not require a upgrade of all the equipment of the data center, which will reduce of the overall expenditure of the data center.

The advantages of 40GBASE-T are clear, but the path from initial ratification to commercial availability is not always smooth. There still a few months off for 40GBASE-T standardization, here comes some good news, as well as some considerations.

40GBASE-T is specified with transmission performance up to 2 GHz (four times the bandwidth of Category 6A) with a lot more stringent alien crosstalk requirements. Since initial 40GBASE-T applications would be limited to data centers, the traditional twisted pair Ethernet 100m link length is not essential. Additionally, Industry players helping in the development of an industry standard for 40GBASE-T have to ensure that it could be supported and rolled out cost-effectively. The new standard will minimize the time it will take to develop new electronics for switches and servers that can support 40GBASE-T connectivity, by building on the work already completed to support 10GbE connections. The standard will also support the ubiquitous RJ-45 connector. Sooner or later, 40GBASE-T will be upon us. Nowadays 40GBASE-LR4, 40GBASE-SR and 40G QSFP+ cables are there to help with the deployment of 40G connectivity. Take JG330A as an example, it is QSFP+ to 4SFP+ Passive Copper Cable available for short reach application. Figure 2 shows a data center twisted-pair migration roadmap.

Summary
BASE-T technology (1000BASE-T, 10GBASE-T or 40GBASE-T) always retains the traditional advantages—low cost, easy to deploy and auto-negotiation for plug and play and backwards compatibility. 1000BASE-T and 10GBASE-T have already brought benefits to people. But no one can foresee that 40GBASE-T will be used in the future but future-proof planning of the cabling is important, given the long life of the cabling systems. Fiberstore provides a full range of BASE-T products including 1000BASE-T SFP, 1000BASE-T media converter, 1000BASE-T GBIC transceiver, etc. And 40GBASE-T devices will be coming soon. If you have any request of our products, please send your inquiry to us.