Driven by Internet-based operations and the increasing demands for time-sensitive delivery of network users, the even higher-bandwidth Ethernet, Gigabit Ethernet (GbE) is evolving. Gigabit Ethernet has been demonstrated to be a viable solution for increased bandwidth requirements for growing networks. With the adoption of 1000BASE-T technology, the dramatic increases in desktop computing power are no longer an issue for some companies or enterprises.
Gigabit Ethernet can be deployed using four different physical layers. Two of these layers use copper cable (1000BASE-T and 1000BASE-CX) and the other two use fiber optic cable (1000BASE-LX and 1000BASE-SX). The purpose of this article is to introduce 1000BASE-T standard and its related products applied in Gigabit Ethernet transmission.
1000BASE-T, also known as IEEE 802.3ab, is a standard for Gigabit Ethernet (1 gigabit is 1000 megabits per second) on copper cables, using four pairs of Category 5 unshielded twisted pair (UTP) to achieve the gigabit data rate. It works by using all four of the Category 5 pairs to achieve 1000 Mbps operation over the installed Category 5 copper cabling. 1000 Mbps data rates are achieved by sending and receiving a 250 Mbps data stream over each of the four pairs simultaneously.
1000BASE-T provides the greatest cost advantage for reliable Gigabit Ethernet. This long-haul, copper-based standard is ideally suited for use within the data center for the following advantages.
Performance—1000BASE-T scales Ethernet 10/100 Mbps performance to 1000 Mbps. Compared with 1Gbps, 1000BASE-T is 100 times as fast as the standard Ethernet. It permits the smooth migration of existing10/100 networks to 1000 Mbps-based networks. When 1000BASE-T technology is deployed in transceiver modules, these 1000BASE-T SFP transceivers, such as Fiberstore compatible Cisco SFP-GE-T and HP JD089B, make shared gigabit service possible and aggregate one gigabit of server support. Both the Cisco SFP-GE-T and HP JD089B listed in Fiberstore support 1000BASE-T operation in host systems with a compact RJ-45 connector assembly. The image below shows an outlook of HP JD089B.
Cost—Used in conjunction with Full Duplex Repeaters (FDRs), 1000BASE-T can provide highly cost-effective shared gigabit service. FDRs offer the traditional low-cost shared media operation of repeaters, but when coupled with 1000BASE-T, they offer an easy-to-manage, high-burst rate, shared-media solution capable of supporting both end users and server farms. In such a case, to aggregate one gigabit of server support is possible in a cost-effective way.
Transmitting a 1000 Mb/s data stream over four pairs of Category 5 twisted pair cables meet several challenges, like signal attenuation, echo, return loss, etc.
Attenuation is the signal loss of the cabling from the transmitter to the receiver. Attenuation increases with frequency, so designers are challenged to use the lowest possible frequency range that is consistent with the required data rate.
Echo is a by-product of dual-duplex operation, where both the transmit and receive signal occupy the same wire pair. The residual transmitted signal because of the trans-hybrid loss combines with the cabling return loss to produce an unwanted signal referred to here as echo.
Return loss is a measure of the amount of power reflected due to cabling impedance mismatches.
Nowadays, 1000BASE-T technology has been adopted by many network designers to boost their network performance in a cost-effective way. Fiberstore supplies a series of 1000BASE-T SFPs, which are compatible with major brands. Besides Cisco and HP, compatible Finisar 1000–T SFP transceivers are also available in Fiberstore, like FCLF-8521-3. You can visit Fiberstore for more information about 1000BASE-T SFP transceivers.
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